A.5.5 instruction code qualifier – Comtech EF Data MBT-4000 User Manual
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MBT-4000 Multi-Band Transceiver System
Revision 4
Remote Control
MN/MBT4000.IOM
A–4
A.5.5 Instruction Code Qualifier
This single character 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)
The = code 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) that follow it. For example: MUT=1 would mean 'enable the Mute
function.'
?
(ASCII code 63)
The ? (ASCII code 63) 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: MUT? Would mean ‘return the current state of the
Mute function.’
2. From Target-to-Controller, the only permitted values are:
=
(ASCII code 61)
The = code is used in two ways:
First, if the Controller has sent a query code to a Target (for example: MUT?
would mean ‘return the current state of the Mute function’), the Target would
then respond with MUT=x, where ‘x’ represents the state in question (1 being
‘enabled’, 2 being ‘disabled).
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 MUT= (with no message arguments).
?
(ASCII code 63)
The ? code 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 MUT? (with no message
arguments). This indicates that there was an error in the argument of the
message sent by the Controller.
!
(ASCII code 33)
The ! code is only used as follows:
If the Controller sends an instruction code that the Target does not recognize,
the Target will acknowledge the message by echoing the invalid instruction,
followed by the ! character; for example, XYZ!
*
(ASCII code 42)
The * code 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 target is in the wrong
mode (e.g., Standby mode in Redundancy configuration) such that it will not
permit that particular parameter to be changed at that time, the Target will
acknowledge the message by replying (for example) with MUT* (with no
message arguments).
#
(ASCII code 35)
The # code is only used as follows:
If the controller sends an instruction code that the target cannot currently perform
because of hardware resource issues, then the target will acknowledge the
message by echoing the invalid instruction, followed by the # character; for
example, MUT# (with no message arguments).