Comtech EF Data XPA-200-OD - Manual (Page 16)

XPA-200-OD Revision 1
Customer Commands MN/XPA200OD.IOM
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2.6.3 I
NSTRUCTION
C
ODE
This is a three-character alphabetic sequence that identifies the subject of the message.
Wherever possible, the instruction codes have been chosen to have some significance.
This aids in the readability of the message, should it be displayed in its raw ASCII form.
Upper case and lower case alphabetic characters may be used (A-Z, and a-z).
2.6.4 I
NSTRUCTION
C
ODE
Q
UALIFIER
This is a single character that 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, MUT=1 would mean ‘enable the
mute function’.
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, MUT? would mean ‘return the
current state of the mute function’.
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)
They have these meanings:
The ‘=’ code (target to controller) is used in two ways: