Mocomtech CDM-570 - Manual (Page 238)

CDM-570/570L Satellite Modem with Optional IP Module Revision 4
Serial Remote Control MN/CDM570L.IOM
13–4
13.5.3 Instruction Code
This is a three-character alphabetic sequence which identifies the subject of the message.
Wherever possible, the instruction codes have been chosen to have some significance.
For example, TFQ stands for transmit frequency, RMD is for receive modulation type,
etc. This aids in the readability of the message, should it be displayed in its raw ASCII
form. Only upper case alphabetic characters may be used (A-Z, ASCII codes 65 - 90).
13.5.4 Instruction Code Qualifier
This is a single character which further qualifies the preceding instruction code.
Code Qualifiers obey the following rules:
1)
From Controller to Target, the only permitted values are:
= (ASCII code 61)
? (ASCII code 63)
They have these meanings:
The = code (controller to target) is used as the assignment operator, and is used to
indicate that the parameter defined by the preceding byte should be set to the value of the
argument(s) which follow it. For example, in a message from controller to target,
TFQ=0950.0000 would mean ‘set the transmit frequency to 950 MHz’.
The ? code (controller to target) is used as the query operator, and is used to indicate that
the target should return the current value of the parameter defined by the preceding byte.
For example, in a message from controller to target, TFQ? would mean ‘return the
current value of the transmit frequency’.
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 43)
^ (ASCII code 94)
They have these meanings:
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 is the Transmit frequency?’), the target would respond with TFQ=xxxx.xxxx,
where xxxx.xxxx represents the frequency in question.