Mocomtech SLM-5650 - Manual (Page 126)

SLM-5650 Satellite Modem Revision 1
Remote Control MN/SLM5650.IOM
B–4
IMPORTANT
The controller sends a packet with the address of a target -
the destination of the packet. When the target responds, the
address used is the same address, to indicate to the
controller the source of the packet. The controller does not
have its own address.
B.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 for transmit frequency, RMD 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).
B.5.4 Instruction Code Qualifier
This is a single character, which further qualifies the preceding instruction code.
Code Qualifiers obey the following rules:
From Controller to Target, the only permitted values are:
Symbol Definition
=
(ASCII code 61) The ‘=’ code is used as the Assignment Operator (AO) 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.
Example: in a message from controller to target, TFQ=0950.0000
would mean “set the transmit frequency to 950 MHz.”
?
(ASCII code 63) The ‘?’ code is used as the Query Operator (QO) and is used to
indicate that the target should return the current value of the
parameters defined by the preceding byte.
Example: in a message from controller to target, TFQ? Would mean
“return the current value of the transmit frequency.”