Open Two Radio Switching Protocol (OTRSP)

Transcription

1 Ope Two Radio Switchig Protocol (OTRSP) Copyright 2009, 2019 Paul Youg. This work is licesed uder the Creative Commos Attributio 3.0 Licese. To view a copy of this licese, visit or sed a letter to Creative Commos, 171 2d Street, Suite 300, Sa Fracisco, Califoria, 94105, USA. Versio Date Author Chage Descriptio Aug 2009 Paul Youg First draft Aug 2009 Paul Youg Reduce umber of tables eeded for commad parsig. Make evets simpler. Add abort Aug 2009 Paul Youg Add reverse stereo Aug 2009 Paul Youg Add serial port speed, CR commad. Rewrite for greater clarity Ja 2010 Paul Youg Add descriptio of SO2R device. Chage wordig for cosistecy (o fuctioal chages) Sept 2010 Paul Youg Add FW commad ad voice keyer commads Jue 2011 Paul Youg Add o-com commuicatios Ja 2019 Paul Youg Multi-radio ad multi-operator extesios OTRSP Versio Prelimiary

2 Summary This is a protocol for commuicatig with a SO2R (Sigle Operator 2 Radio) device. It is a serial protocol ad is suitable for use o a physical or virtual serial port or other commuicatios chael. It is iteded to replace the LPT port which has historically bee used to cotrol a SO2R device ad to offer features which could ot be supported by the LPT port. This is a ope protocol. The authors disclaim ay proprietary or itellectual property rights to it. It may be implemeted by ayoe for ay legal purpose. SO2R Device A SO2R device is a device which coects to two radios ad allows a operator to select which radio is to be used for trasmittig ad receivig. The device provides a iterlockig capability oly oe trasmitter ca trasmit at a time. It may be possible for two receivers to be used at oce The SO2R device may optioally support a stereo mode where oe receiver is heard i each ear. The trasmitter which is selected is said to have trasmit focus. The receiver or receivers which are selected are said to have receive focus. The selectio of trasmit ad receive focus ca be cotrolled by the computer usig the OTRSP commads described i this documet. The SO2R device may optioally also have override capabilities where a operator ca force a specific trasmitter or receiver to have focus. A SO2R device may switch the microphoe, CW key, ad PTT sigals to a specific radio i order to give that radio trasmit focus. A SO2R device may optioally have a PTT switch or a coector for a exteral PTT pushbutto or footswitch. The SO2R device will coect this to the trasmitter which has focus. Usually the computer ca also set PTT. A SO2R device may optioally have auxiliary outputs. Typically if it has them it would have oe or two groups of four bit outputs. These ca be cotrolled by the computer. They are typically used for atea selectio. Although ot strictly part of SO2R operatio they have historically bee icluded i SO2R hardware. A SO2R device may optioally have cotrol iputs. These usually have o direct effect o the SO2R Box or the radios but a computer program ca read the values ad make chages based o them. The exceptio is the PTT switch which, if it exists, is a cotrol but also ca switch a radio from receive to trasmit. Figure 1 shows a example SO2R device. The microprocessor commuicates with the computer usig the OTRSP protocol ad it cotrols circuitry which switches the microphoe, key, PTT, ad headphoes. OTRSP Versio Prelimiary

3 Figure 1. A SO2R device A SO2R device may ot implemet all of these features. For example, it may ot have ay Aux outputs or additioal cotrols, ad there may be o maual override for the computer s trasmit ad receive focus selectio. Additioal devices may be packaged with the SO2R device. For example a box may also cotai a CW keyer or a soud card. These do ot affect the SO2R OTRSP fuctios. A SO2R device may optioally be able to cotrol more tha two radios. The OTRSP commads ca oly set trasmit ad receive focus for two radios. There is a commad which specifies which two radios to use. Serial Port Characteristics The stadard port parameters for a OTRSP SO2R device are 9600 baud, o parity, 8 bit data, oe stop bit. PTT ad CW PTT ad CW keyig ca be cotrolled by the serial port lies RTS ad DTR respectively. Support for PTT ad CW keyig are optioal, as they ca be doe i other ways, for example through a keyer. PTT is equivalet to LPT port pi 16. CW is equivalet to LPT port pi 17. OTRSP Versio Prelimiary

4 Note: It is possible for PTT ad CW to be implemeted usig RTS ad DTR o a serial port other tha the oe used for OTRSP commads. Commads, Resposes, ad Evets A commad is a strig of characters set from the cotrollig program to the SO2R device. A respose is a strig of characters set by the SO2R device to the cotrollig program i respose to a commad. A evet is a strig of characters set by the SO2R device to the cotrollig program i respose to a state chage i the SO2R device. All characters are from the UTF-8 character set. All commads, resposes, ad evets are termiated by a carriage retur, UTF-8 character 13. The carriage retur is represeted i this documet by the digbat. The parts of a commad are: Query Prefix Keyword Item Value Carriage Retur Sigle character?. If the query prefix is preset the commad is a query. Oe to six characters. The keyword idetifies the commad. Sigle digit, 0-9. May or may ot exist, depedig o the commad. Idetifies a particular item, such as a port or radio. Oe or more characters. Always preset if the commad is ot a query. Termiates a commad. There is o delimiter betwee the parts of a commad. Commads which are ot query commads will have a keyword, possibly a item ad a value. Commads which are query commads will have the query prefix, a keyword, ad possibly a item. All o-query commads have a equivalet query commad, which is the keyword ad possibly the item prefixed with the query prefix. The SO2R device respose will be the commad which would set the curret value. All commad ad evet strigs are at most 16 characters i legth. All resposes are less tha 40 characters i legth. These legths iclude the retur character. If a urecogized commad which is ot a query commad is set, the SO2R device will igore it. If a urecogized query commad is set, the SO2R device will respod with the same commad, icludig the questio mark. For example, if the cotrol program set?abc the SO2R device OTRSP Versio Prelimiary

5 would respod?abc. This ca be used to fid out if a commad is implemeted by the SO2R Device. If a query prefix with o keyword is set, the the respose will be the query prefix. I other words, if the cotrol program seds? the SO2R device will respod?. This ca be used as a pig commad to verify that the SO2R device is preset. All commads begiig with the letter V are reserved ad vedor specific. A vedor might use commads for device specific fuctios such as firmware update or device-specific status. These are ot meat for ormal SO2R device features. If a ew feature is desired a vedor should propose a ew commad to be added to the protocol so that all vedors who support the feature will do so i the same way. Supported Commads This is the complete set of commads (other tha the voice keyer extesio) as of this versio of the protocol: Commad TX Item Value Set which radio has trasmit focus. The values of are 1 ad 2. The?TX commad returs the actual radio which has trasmit focus, which may be differet tha what was set by the previous TX commad if the device selectio has bee overridde, for example by a frot pael switch o the SO2R device. This is the equivalet of LPT port pis 3 ad 14. RX Set which radios have receive focus, possibly receivig i stereo. The values of are 1, 2, 1S, 2S, 1R, ad 2R. There are four choices for what radio or radios are coected to the headphoes. a. Radio 1 is coected to both headphoes. b. Radio 2 is coected to both headphoes. c. Radio 1 is coected to the left headphoe ad radio 2 is coected to the right headphoe. This is called stereo. d. Radio 1 is coected to the right headphoe ad radio 2 is coected to the left headphoe. This is called reverse stereo. Not all SO2R devices support all of these modes. The value has iformatio for a SO2R device to use a mode it supports. These are the values ad what they mea: OTRSP Versio Prelimiary

6 Value Fuctio 1 Coect radio 1 to both headphoes. 2 Coect radio 2 to both headphoes. 1S 2S 1R 2R Coect radio 1 to the left headphoe ad radio 2 to the right headphoe (stereo). If stereo is ot possible coect radio 1 to both headphoes. Coect radio 1 to the left headphoe ad radio 2 to the right headphoe (stereo). If stereo is ot possible coect radio 2 to both headphoes. Coect radio 1 to the right headphoe ad radio 2 to the left headphoe (reverse stereo). If reverse stereo is ot possible coect radio 1 to the left headphoe ad radio 2 to the right headphoe (stereo). If stereo is ot possible coect radio 1 to both headphoes. Coect radio 1 to the right headphoe ad radio 2 to the left headphoe (reverse stereo). If reverse stereo is ot possible coect radio 1 to the left headphoe ad radio 2 to the right headphoe (stereo). If stereo is ot possible coect radio 2 to both headphoes. The?RX commad returs the mode actually set for the receivig radio which may be differet tha what was set by the previous RX commad if the SO2R device does ot support the requested mode or if the device selectio has bee overridde, for example by a frot pael switch o the SO2R device. Receiver selectio is the equivalet of LPT port pi 4. Stereo selectio is the equivalet of LPT port 5. AUX x Sets the auxiliary port. x is the port umber. The values of x are 0-9. The value of is a oe to three digit decimal umber. The value of is If the auxiliary port does ot exist the commad is igored. If the value is larger tha the port supports the high order bits will be igored. There is a covetio that auxiliary port 1 cotais bad or atea iformatio for radio 1 ad auxiliary port 2 cotais bad or atea iformatio for radio 2. The?AUXx commad returs the value actually set for a port ad will ot iclude bits which were igored. For example, if port 1 is 4 bits, the commad AUX125 will set the value to 9 ad?aux1 will retur AUX19. If a port does ot exist the respose to a query for that port would be that the commad does ot exist. For example,?aux0 would retur?aux0 if there is o port 0. OTRSP Versio Prelimiary

7 Auxiliary port 1 is equivalet to LPT port pis 2, 7, 8, 9. BAND x Tells the SO2R device the bad iformatio for a radio. x is the radio umber. The values of x are 1 or 2. The value of is the frequecy i MHz of the bottom of the bad, for example 3.5 or 144. If the bad is ot set?band would retur BAND0. MODE x Tells the SO2R device the mode iformatio for a radio. x is the radio umber. The values of x are 1 or 2. The value of is C for CW, U for USB, L for LSB, R for RTTY, F for FM, A for AM, X for other. If the mode is ot set?mode would retur MODE0. MAP x Tells the SO2R device to map a physical radio to oe of the two radios specified i the TX ad RX commads. X is the radio umber. The values of x are 1 or 2. The value of is a oe to three digit umber correspodig to the physical radio. This commad is iteded for SO2R devices which support more tha two radios. It is ot eeded for a SO2R device which supports oly two radios. If this commad is ot implemeted it is assumed that radio 1 specified i the TX ad RX commads is always physical radio 1 ad radio 2 is always physical radio 2. The cotrollig program should ot issue this commad uless it is prepared to deal with a SO2R device havig more tha two radios coected. NAME Sets the ame of the SO2R device. The value of is the ame to set the SO2R device to. This commad is usually igored. The?NAME commad is more useful as it returs the ame of the SO2R device. The maximum legth of the ame is 32 bytes. It is valid to use characters from the multibyte UTF-8 character set but be aware that some programs might ot hadle these characters correctly. FW Sets the firmware versio of the SO2R device. The value of is the firmware versio to set the SO2R device to. The format of the firmware versio is x.y.z where x is the major OTRSP Versio Prelimiary

8 versio, y is the mior versio, ad z is the product or patch versio. x, y, ad z are oe to three digit umbers with optioal leadig zeros. This commad is usually igored. The?FW commad is more useful as it returs the firmware versio of the SO2R device. CR x Sets the value of a cotrol. x is the cotrol. The values of x are 0-9. The value of is the value to set the cotrol to. This commad is usually igored, as cotrols usually caot be writte to. The?CR commad is more useful because it returs the curret value of the cotrol. Cotrols ca be items such as switches, which will retur values 0 if ope ad 1 if closed, or a more complex cotrol which ca retur a value betwee 0 ad 255. CR0 is reserved for a PTT switch which is kow to have the side effect of activatig the trasmitter which has trasmit focus. ERX Eable RX evets. The value of is 1 to eable the evets ad 0 to disable the evets. See the Usolicited Evets sectio for more details. ETX Eable TX evets. The value of is 1 to eable the evets ad 0 to disable the evets. See the Usolicited Evets sectio for more details. ECR x Eables evets for a cotrol. The values of x are 0-9. The value of is 1 to eable the evets ad 0 to disable the evets. See the Usolicited Evets sectio for more details. Usolicited Evets If usolicited evets are eabled the SO2R device may sed usolicited strigs to the cotrollig program. All usolicited evets are disabled by default. The evet will start with the $ character, followed by the evet ame, item umber if used, value, ad a carriage retur. Eablig a evet which has a value causes it to immediately sed a evet strig with the curret value of the evet. The evets curretly defied are: Evet Item Value OTRSP Versio Prelimiary

9 RX The receiver selectio has chaged. The values of are 1, 1S, 1R, 2, 2R, ad 2S. The chage could be i respose to a commad or to a chage i the SO2R device, such as a user throwig a switch to set the receiver. TX The trasmit focus has chaged. The values of are 1 or 2. The chage could be i respose to a commad or to a chage i the SO2R device such as a user throwig a switch to set the trasmitter. AB The user has doe somethig bad, such as tryig to chage the trasmit focus while PTT is set. The cotrollig program should abort ay trasmissio if possible. CR x A cotrol has bee chaged. x is the cotrol idex. is the value, which ca rage from 0 to 255, expressed as a oe to three digit iteger. Switches ormally have values of 0 for ope ad 1 for closed. Timig ad Sychroizatio The SO2R device operates as a sychroous device. Commads are executed i order. A commad completes before the ext commad is started. A SO2R device is expected to be able to accept characters while it is sedig characters. It is ot ecessary for the cotrol program to wait for the result of a query before sedig aother commad. There is a limit to how fast commads ca be set to a SO2R device. Normally at least five commads ca be set at a time. However the SO2R device may have a buffer as small as 64 characters so if log commads are set it may lose characters. Also the SO2R device may have a limited output buffer size. If may queries are set this buffer could be filled. Sice most queries are almost the same legth as their resposes this should ot be a problem i ormal use. Note that the?name commad may sed a loger respose tha other commads. The SO2R device must ot sed evets frequetly eough that they will overru a ormal commuicatios buffer. A SO2R device is expected to respod to a query withi 250 ms. OTRSP Versio Prelimiary

10 Commad examples TX1 RX2S AUX17?AUX9 MODE1L?NAME?FW?XXXX?CR0 ECR21 Future trasmissios will be from radio 1. Receive stereo if possible, otherwise from radio 2. Set the value of the auxiliary port 1 pis to 7. If there is a aux 9 port the the SO2R device would respod AUX9 where is the curret value o the port. If there is o aux 9 port the so2r device would respod?aux9. Radio 1 has bee set to lower sidebad. The SO2R device respods NAME followed by the ame of the device followed by a carriage retur. If the device was amed SO2R Device it would respod with NAMESO2R The SO2R device respods FW followed by the firmware versio of the device followed by a carriage retur. If the major versio was 1, the mior was 2, ad the patch was 34 it could respod with FW XXXX is ot a kow commad. Reply?XXXX. Returs the value of the CR0 cotrol. The device replies with the curret value. This is ormally a PTT switch. If the switch was closed it would respod CR01. If the switch was ope it would respod CR00. If there is o PTT switch it would respod?cr0. OTRSP Versio Prelimiary

11 ?ECR2 EAB1 TX1?TX TX1 RX1?TX?RX Eable evet CR2. The device replies with a evet that cotais the curret value of CR2. If CR2 were a footswitch which was ot pressed it would reply $CR20. If the switch were later pressed it would sed $CR21. If the SO2R device does ot have a CR2 cotrol there will be o respose. Returs ECR21 if the CR2 evet is eabled or ECR20 if ot. If the SO2R device does ot have a CR2 cotrol it will respod?ecr2. Turs o the abort evet. There is o respose. If the SO2R device wats trasmissio to cease it will sed $AB. Future trasmissios will be from radio 1. The device will respod TX1. It will ot respod util the trasmit focus has bee set to radio 1. Future trasmissios will be from radio 1. Radio 1 will be the receivig radio. The device will respod TX1 RX1 after radio 1 has trasmit ad receive focus. Miimum Device Implemetatio A SO2R Device must implemet the followig: The TX ad RX commads ad the?tx ad?rx commads. The AUX commad ad?aux commad if it has ay Auxiliary ports. The?NAME commad. For?<commad> where the commad or item is ot recogized, retur the the commad umodified. It should be capable of operatio o a port set to 9600 baud, o parity, 8 data bits, 1 stop bit. Miimum Cotrol Program Implemetatio A cotrol program could replace LPT port SO2R cotrol with this protocol by implemetig the followig: OTRSP Versio Prelimiary

12 The TX1, TX2, RX1, RX2, RX1S, RX2S, RX1R, ad RX2R commads. RX1R ad RX2R ca be treated as RX1S ad RX2S. RTS as a PTT cotrol if appropriate. The AUX1 commad if the cotrol program supports sedig bad or atea iformatio. Note that the SO2R device will ever sed ay characters uless a commad is set that causes a respose or a evet is eabled. A miimum implemetatio ca sed commads ad ever eeds to read aythig. If the cotrol program sets the speed of the serial lie it should be capable of settig it to 9600 baud. Cotrol program ehacemets Sed?NAME after coectig to the SO2R device ad display or log the result. If the cotrol program ca provide iformatio for two radios use the AUX2 commad to put out this iformatio for the secod radio. If the SO2R device is kow to be very slow it might be prudet to sed a TX commad followed by a?tx commad ad to wait for the result before trasmittig. Sed the BAND ad MODE commads. The SO2R device will igore them if it has ot implemeted them. Eable the abort evet ad stop trasmittig if a abort evet is received. This ca help protect a good statio from a bad operator. Eable evets for receive ad trasmit selectio ad set trasmit ad receive focus if they are differet tha the curret selectios. Eable evets for a couple cotrols ad allow them to be mapped to useful fuctios, for example allowig a footswitch cotrol to chage focus. Use the MAP commad to hadle more tha two radios. Voice Keyer Extesio OTRSP ca be used to cotrol a voice keyer. This uses additioal commads ad evets. The commads ad evets will ot be recogized by a SO2R box which does ot implemet a voice keyer. OTRSP Versio Prelimiary

13 The voice keyer is ot strictly part of a SO2R device but there are several SO2R devices with itegrated voice keyers. The voice keyer logically is betwee the microphoe ad the microphoe switch. The voice keyer is expected to assert PTT whe it plays a message ad to drop PTT whe it fiishes or aborts the message. Supported Voice Keyer Commads Commad KR Item Value Starts recordig a message. is the message umber, which ca rage from 1 to 255, expressed as a oe to three digit iteger. Not all voice keyers support all message umbers. The?KR commad returs the message umber of the message curretly beig recorded or 0 if o message is beig recorded. KS Stops recordig. The commad has o effect if a message is ot beig recorded. The?KS commad returs KS. KP Starts playig a message. N is the message umber, which ca rage from 1 to 255. The behavior of the KP commad whe the voice keyer is already playig a message is ot defied. The?KP commad returs the message umber of the message curretly playig or 0 if o message is beig played. KA Aborts ay message which is beig played. The commad has o effect if a message is ot beig played. The?KA commad returs KA. EKR Eable voice keyer record evets. The value of is 1 to eable the evets ad 0 to disable the evets. See the Usolicited Voice Keyer Evets sectio for more details. EKP Eable voice keyer play evets. The value of is 1 to eable the evets ad 0 to disable the evets. See the Usolicited Voice Keyer Evets sectio for more details. Usolicited Voice Keyer Evets The voice keyer ca sed usolicited evets if they are eabled. OTRSP Versio Prelimiary

14 The evets curretly defied are: Evet Item Value KR The voice keyer has started or stopped recordig. The value of is the message umber or 0 if the voice keyer has stopped recordig. KP The keyer has started or stopped playig. The value of is the message umber or 0 if the keyer has stopped playig. Voice Keyer commad examples KR1 KS KP1 KA?KR EKP1 Start recordig message 1. Fiish recordig the message beig recorded. Start playig message 1. Abort the curretly playig message. Returs the umber of the message curretly beig recorded. If message 1 is beig recorded the device will respod KR1. If o message is beig recorded the device will respod KR0. If the SO2R device does ot have a voice keyer it will respod?kr. Eable voice keyer playback evets. The device replies with a evet that cotais the curret message beig played, or 0 if o message is beig played. If message 2 is beig played it would reply $KP2. If the SO2R device does ot have a voice keyer there will be o respose. Commuicatios over Other Chaels The OTRSP protocol was origially desiged to be used with serial ports with RTS ad DTR capabilities. It ca be used with other iterfaces such as amed pipes. Other iterfaces do ot OTRSP Versio Prelimiary

15 provide modem sigals, therefore a additioal commad is eeded to cotrol PTT. This commad is oly supported whe RTS is ot available. Commad X Item Value Turs PTT o or off. PTT is tured o if the is 1, ad off if it is 0. Commad examples X1?X Tur o PTT. Returs X1 if PTT has bee tured o usig the X commad ad X0 otherwise. If the SO2R device is ot supportig this commad it will retur?x. Some commuicatios mechaisms are message orieted. For example, Widows amed pipes are usually used i message mode. There is o requiremet that commads have ay correspodece with messages. It is recommeded that a SO2R device usig such a mechaism accept messages of at least 40 characters ad that it sed oe character per message. Multi-Radio ad Multi-Operator Extesios The OTRSP protocol hadles two radios at a time ad provide for a sigle stereo output. This optioal extesio allow cotrol of additioal radios ad outputs. Up to 36 radios ad 36 stereo outputs ca be supported. Although radios may use the umbers 0 9, for iteroperability with loggig program implemetatios which do ot use exteded commads, the first radio should be radio 1 ad the secod should be radio 2. Extesios to supported commads These are the commads which have exteded values. Their use is backwards compatible with o-exteded implemetatios: Commad TX Item Value Set which radio has trasmit focus. The value of ca be ay umeric digit or upper case alphabetic character (0 9 or A Z). The?TX commad returs the actual radio which has trasmit focus, which may be differet tha what was set by the previous TX commad if OTRSP Versio Prelimiary

16 the device selectio has bee overridde, for example by a frot pael switch o the SO2R device, or if the specified TX device does ot exist. MAP x Tells the SO2R device to map a physical radio to oe of the radios specified i the TX, RX, ad PH commads. The item is the radio umber. The value of x ca be ay umeric digit or upper case alphabetic character (0 9 or A Z). The value of is a oe to three digit umber correspodig to the physical radio. This commad is iteded for SO2R devices which support more tha two radios. It is ot eeded for a SO2R device which supports oly two radios. If this commad is ot implemeted it is assumed that radio 1 specified i the TX, RX, ad PH commads is always physical radio 1, radio 2 is always physical radio 2 etc. Supported Multi-Radio ad Multi-Operator commads These are the commads which have exteded values. Their use is backwards compatible with o-exteded implemetatios: Commad Item Value PH x Set which radios are coected to a pair of headphoes. The item is the headphoes. The value of x ca be ay umeric digit or upper case alphabetic character (0 9 or A Z). The value of is a list of which radio outputs are coected to the headphoes. Each radio has two outputs, left ad right. These outputs could be coected to the left or right headphoes chael. The strig cotais the radios for the left headphoes chael, a dot, ad the radios for the right chael. A radio s left or right chael is specified by usig the left or right brackets before the radio umber. For example [1 is radio oe left chael ad ]2 is radio 2 right chael. A bracket effects all radios specified after it util the ext bracket is see. For example [12 specifies the left chaels of radio 1 ad radio 2. If a bracket is ot specified before the first radio a left bracket is assumed. If the device is ot capable of coectig multiple radio chaels to a headphoe chael the first specified radio chael will be used. If the specified radio chael caot be coected to the specified device the result is devicedepedet. It may coect a differet chael or make o coectio. EPH x OTRSP Versio Prelimiary

17 Eables PH evets. The item is the headphoes. The value of x ca be ay umeric digit or upper case alphabetic character (0 9 or A Z). The value of is 1 to eable the evets ad 0 to disable the evets. See the Usolicited Evets sectio for more details. Commad examples PH11.2 PH11.]1 PH113.2]3 EPH21 Headphoes 1 will liste to radio 1 left chael i the left ear ad radio 2 left chael i the right ear. Headphoes 1 will liste to radio 1 left chael i the left ear ad radio 1 right chael i the right ear. Headphoes 1 will liste to radio 1 left chael ad radio 3 left chael i the left ear ad radio 2 left chael ad radio 3 right chael i the right ear. Eable evet for headphoes 2. The device replies with a evet that cotais the curret value of headphoes 2. If the SO2R device does ot have headphoes 2 there will be o respose. Compatibility If radios other tha 1 ad 2 are used for TX the?tx commad ad TX evets will show trasmitters other tha 1 or 2. This could be a problem if a loggig program which does ot implemet multi-radio extesios rus after a loggig program that does. The RX commad always operates o the same chaels as PH1. Headphoes 1 ca be chaged usig either commad. The?RX query ad RX evets may be icapable of showig the results of a PH commad. If the PH commad is used the the?rx commad may show iformatio which is completely icorrect. PH commads may ot trigger RX evets. If a PH commad coects receivers to headphoes 1 i a way that matches a RX commad the the result of a RX query should be correct. If the RX commad is used the the?ph1 commad must correctly show the selected radio chaels. OTRSP Versio Prelimiary