C.5.6 Optional Message Arguments; C.5.7 End Of Packet - Comtech EF Data SLM-5650A Installation And Operation Manual

SLM-5650A Satellite Modem
Appendix C
2. From Target-to-Controller, the only permitted values are:
Symbol
=
(ASCII code 61)
?
(ASCII code 63)
!
(ASCII code 33)
*
(ASCII code 42)
#
ASCI code 35)
C.5.6 Optional Message Arguments
Arguments are not required for all messages. Arguments are ASCII codes for the characters 0 to 9 (ASCII codes 48 to 57), period (ASCII
code 46) and comma (ASCII code 44).
C.5.7 End Of Packet
Controller-to-Target: This is the 'Carriage Return' character (ASCII code 13).
Target-to-Controller: This is the two-character sequence 'Carriage Return', 'Line Feed' (ASCII codes 13 and 10). Both indicate the
valid termination of a packet.
Definition
The '=' code is used in two ways:
a. If the Controller has sent a query code to a Target
(Example: TFQ? (meaning 'what's the Transmit frequency?'), the Target would respond with TFQ=xxxx.xxxx, where xxxx.xxxx
represents the frequency in question.
b. If the Controller sends an instruction to set a parameter to a particular value, then, providing the value sent is valid, the Target will
acknowledge the message by replying with TFQ=(with no message arguments)
If the Controller sends an instruction to set a parameter to a particular value, then, if the value sent 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.
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!
If the Controller sends an instruction to set a parameter to a particular value, then, if the value sent is valid, BUT the modulator will not
permit that particular parameter to be changed at this time, the Target will acknowledge the message by replying (for example) with
TFQ* (with message arguments).
If the Controller sends a correctly formatted command, BUT the modulator is not in remote mode, it will not allow reconfiguration and
will respond with TFQ#
C–5
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MN-SLM5650A