Campbell Scientific SC932C Interface - Manual (Page 10)

APPENDIX B. TECHNICAL DETAILS OF SPECIAL MODES OF OPERATION
B-2
1
2
4
5
6
9
1
2
5
9
Datalogger
Pin No.
SC932C
9-Pin D
Pin No.
No connection to SC932C
No connection to SC932C
FIGURE B-1. Connections for Using SC932C in ‘Printer’ Mode
(Other wires can be left connected or
disconnected.)
With this connection the SC932C can be
connected in parallel to another Campbell
Scientific modem-type device. However, as
with the SC932, any data output to synchronous
devices (e.g., a Storage Module) will also be
transmitted out through the RS232 connection.
B.4 MAXIMUM RECALL INTERVAL
From the time that the datalogger leaves
communications mode (ME goes low), there is
a delay of approximately one second before
serial or ring line activity from the RS232 device
will re-awaken the datalogger. This prevents
spurious messages from the RS232 device
(such as ‘loss of carrier’ messages from a
modem) waking up the datalogger. The only
consequence of this delay is that specialized
software which polls dataloggers at frequent
intervals will not be able to wake the same
datalogger again during the delay period.
Campbell Scientific are aware of some modems
which will re-trigger the ring line, despite this
delay. The only consequence of this is that the
datalogger will remain in communications mode
for an extra 30 seconds after the end of the call;
this will waste a small amount of power and
delay any output to a Storage Module.