Comtech EF Data CDM-Qx, Installation And Operation Manual

Page: 171 / 224

CDM-Qx Satellite Modem Revision 6
Remote Control MN/CDMQx.IOM
2. From Target to Controller, the only permitted values are:
=
(ASCII code 61)
? (ASCII code 63)
! (ASCII code 33)
* (ASCII code 42)
# (ASCII code 35)
~
(ASCII code 126)
$ (ASCII code 36)
^ (ASCII code 94)
@ (ASCII code 64)
They have these meaning:
The ‘=’ code (Target to Controller) is used in two ways:
First, if the controller has sent a query code to a target (for example TFQ?, meaning
‘what’s the Transmit frequency?’), the target would respond with TFQ=xxxx.xxxx,
where xxxx.xxxx represents the frequency in question.
Second, if the controller sends an instruction to set a parameter to a particular value, then,
providing the value sent in the argument is valid, the target will acknowledge the
message by replying with TFQ= (with no message arguments).
The ? code (Target to Controller) is only used as follows:
If the controller sends an instruction to set a parameter to a particular value, then, if the
value sent in the argument is not valid, the target will acknowledge the message by
replying (for example) with TFQ? (with no message arguments). This indicates that there
was an error in the message sent by the controller.
The * code (Target to Controller) is only used as follows:
If the controller sends an instruction to set a parameter to a particular value, then, if the
value sent in the argument is valid, BUT the modem will not permit that particular
parameter to be changed at that time, the target will acknowledge the message by
replying (for example) with TFQ* (with no message arguments).
The ! code (Target to Controller) is only used as follows:
If the controller sends an instruction code which the target does not recognize, the target
will acknowledge the message by echoing the invalid instruction, followed by the !
character with. Example: XYZ!
The # code (Target to Controller) is only used as follows:
If the controller sends a correctly formatted command, BUT the modem is not in remote
mode, it will not allow reconfiguration, and will respond with TFQ#.
The ~ code (Target to Controller) is only used as follows:
If a message was sent via a local modem to a distant end device or ODU, the message
was transmitted transparently through the local modem. In the event of the distant-end
device not responding, the local modem would generate a response e.g. 0001/RET
~ ,
C-5