help with protocol for an AV router

[mdavison69]

Hello,

I am hoping to build a small program for use at my work. what i want to do is control an old di-tech 20x40 AV Matrix router. i have a protocol, and a cable made for it. If it matters to anyone it is a modfied serial cable that will go between a serial port on a pc to a serial port on an interface panel. What i need to know is, if i am going about this right. i have the actual protocol, which i will paste below. for starters can i create and execute a command in dos using a serial port to control the router - for testing purposes. - i dont even know if the cable is exactly correct for sure.

the below command should make a switch to destination 003 from source 013 for video and all audio on site #2, using a dos command

@echo $SS20130031! > com1

This should work right? i have tried many variations of this with no luck. Can i even use dos to make a comand like this? Hopefully i have placed this question in the right place.




Di-Tech Model 9740 Unix Connector Protocol

PHYSICAL I/O
The connector for is located on the back of the 9740 and is a 15 Pin Male ‘D’ connector.
All commands to the 9740 and attached switcher are done thru this connector. The interface between the 9740 and the Di-Tech switcher is a 37 conductor cable. This is a parallel bus.
Pin = 2 ?, Data into the 9740
Pin = 3 ?, Data out from the 9740
Pin = 7 ?, Ground.
COMMUNICATIONS
9600 Baud, 1 Start Byte, 8 Data Bytes, 1 Stop Byte.
No hardware or software handshaking is used.
PROTOCOL DEFINITIONS. ALL BYTES IN STRING ARE ASCII
Spaces in command strings are only shown for clarity. Do not send spaces.
$ = Start Byte
Command Type = 2 Bytes, SS, TS, etc.
<site #> = Site number, 1 Byte, 1 to 8. Site 1 is local 9740 which receives commands from your controller. It will relay commands to remote 9740’s, site 2 – 8, if any.
<src #> = Source # (Input), 000 - 255, 3 Bytes.
<dst #> = Destination # (Output), 000 - 255, 3 Bytes
<brk> = Breakaway type, 1 = A/V, 2 = Audio Only, 3 = Video Only.
! = End Byte
___________________________________________________________________
Switch Command to 9740
$ SS <site #> <src #> <dst #> <brk> !
Responses from 9740 will be:
Switch OK = $ DG <site_#> ! or Data Bad = $ DB <site_#> !
If the switch if for a remote 9740, sites 2 – 8, an additional response is valid, $ NR <site_#> ! = no response from remote
_____________________________________________________________
TALLY (STATUS) REQUEST COMMAND
$ TS <site_#> <dst_#> !
Responses from 9740 will be:
$ ST <site_#> <dst_#> <vid_#> <aud_#> ! = Actual tally of switcher.
OR
$ MF <site_#> <pin_#> ! = an alarm was triggered on the 9740 Message Connector,
Pin numbers range from 1 to 22. <pin #> is 2 Bytes.
OR
$ MS site_#> <dst_#> <vid_#> <aud_#> ! = a manual switch is made from the 9740 front panel or touch tone input.
OR
$ DB <site_#> ! = Data Bad
If the switch if for a remote 9740, sites 2 – 8, an additional response is valid, $ NR <site_#> ! = no response from remote

[mdavison69]

Maybe i rambled a little too much.

What is the proper way to send a command to the com port?

@echo xxxxxx >com1