Philips System 21 Quick Operating Manual page 24

Requested data
Command data
Description
Response data
•
Slave-status
" S ?
"
Ask for the status of the unit.
Response: " S
" +
<9 digits>
A non-zero digit represents one of
the messages given below. A zero
digit means that the message
belonging to the position of the
digit in the string, is not true.
Digits: "1"
Power-on reset or power fail.
(flags)
" 2" Alarm (not applicable to all units).
This event can only be masked by
the " MSR ''command (" MSR 128" )
but this masks all System 21
events.
" 3"
Illegal code received (programming
error).
"4" Functional commands are
cancelled because of an illegal
command sequence.
" 5"
Data available; unit should be read.
" 6" Busy with a block or a scan.
" 7"
Warning 1
J
" 8" Warning 2 specified per unit
" 9"
Warning 3
The message - flags , except digits
" 5" and " 6", are reset after
" S ? " with the next IEEE/IEC-bus
input.
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