User`s guide

Call-Back Configuration for the CR800/CR1000 – MultiLogger Application Note #19 – Page 6 of 12
For example, the following code will re-activate call-back after measurements return to normal or a certain
number of iterations of the scan interval are passed. You will need to label an Input Location named
CallBackReset for this programming to function correctly. See the previous sections on using the
Configure Input Locations form to label a location.
'Check for Alarm
if mlFlag8 then
'Check if our Call-back resets should be reset
if CallBackReset >= 8 then CallBackReset = 0
'Check if first Call-back or we just reset it
if CallBackReset = 0 then
'Make sure AbortExp is reset
CallBackAbort = 0
'Initiate call-back
ModemCallBack(CallBackStatus,ComSDC7,-115200,0,"nnnnnnnnnn","",60,120,CallBackAbort)
'Increment our CallBackReset counter
CallBackReset = CallBackReset + 1
endif
else
'Reset our Call-back counter
CallBackReset = 0
endif
Note the Reset Count parameter highlighted in the code, this configures the number of repetitions of the
scan interval before another call-back attempt will be initiated. For example, if the Single Interval is
configured for 15 Minutes, then even if alarms persist another call-back attempt will not initiated for 2
hours (8 * 15 minutes).
Note: It is very important to optimize the call-back configuration with the number of systems and
other considerations for accessibility to the remote sites and/or originating computer. For
example, if the Single Interval is 1 minute then avoid configuring a potential call-back with every
scan interval, otherwise the system could become inaccessible with continued outgoing call-back
attempts. Another example - multiple systems configured for call-back with a short interval.
Consider a deployment with 15 systems all configured for continuous 15-minute call-backs. In this
case alarms generated on multiple systems could cause the originating computer and modem to
become unusable with negotiating multiple incoming calls.
Additional RS-232 Modem Call-Back Guidelines
When using the RS-232 port on the CR800/CR1000 with a connected modem keep the following in mind:
• The modem must output the RING signal to turn on the CR800/CR1000 RS-232 port, alternately
additional characters can be sent out TXD to turn the port on. DTR will be asserted once the port
is turned on. You may also disable DTR handling in the modem.
• Make sure the baud rate configured in the call-back programming matches the supported baud
rate for the connected modem. Usually it is best to fix the baud rate of the connected modem.
See the modem documentation for the command to fix the baud rate.
• The cable (wiring below) must include a null-modem adaptor as the CR800/CR1000 RS-232
ports are configured DCE (Data Communications Equipment), modems are also DCE.
CR800/CR1000 DB-9F Null-Modem to Modem DB-9F and DB-25F wiring diagrams are as follows:
CR800/1000
DB-9F Pin
Description
CR800/1000
I/O
Modem
DB-9F Pin
Modem
DB-25F Pin
1
DTR – Data Terminal Ready O 4 20
2
TXD – Transmit Data O 3 2
3
RXD – Receive Data I 2 3
4
No Connection Jumper 1&6 Jumper 6&8
5
GND – Ground 5 7
6
DTR – Data Terminal Ready O
7
CTS – Clear to Send I 8 5
8
RTS – Request to Send O 7 4
9
RING – Ring signal I 9 22
Reset Count