My setup is as follows.
There are 3 CR3000 data loggers installed in a remote location.
Logger 1 is the master. Logger 2 is connected to Logger 1 via COM1 Rx/Tx. Logger 3 is connected to Logger 1 via COM2 Rx/Tx. Logger 1 is communicating with an Iridium 9522B satellite modem via the RS-232 9-pin interface connector.
We communicate with the remote system using a PC (LoggerNet 4.2) that is connected to the Internet / Iridium Server with a static IP connection. We use MT (mobile terminated) calls only. LoggerNet initiates data transfers by calling the modem's Iridium number then uses PakBus for the actual data transfer.
This setup has worked for several weeks with scheduled transfers without any problem. Recently we needed to update the CRBasic program running in the loggers, so I used the File Control screen to do the update. The low-level communication was monitored by the virtual COM port software (NetDialOut).
I established a connection with the Connect screen -> Connect button. On the File Control screen I stopped the running program with the "Delete all data" option then transferred the new program with "Run Now", "Run on Power Up" and "Erase all data" options.
This procedure was successful with Logger3 and the new program is running properly. I repeated the same procedure for Logger 2 but unfortunately the satellite connection was broken while the CF card was being erased. I saw on the low-level monitor the "keep alive" packets received by LoggerNet then all the sudden all communications stopped and the modem reported NO CARRIER.
Since then the site has not communicated. I can dial the modem and it reports "CONNECT 9600"; I see the ring packets sent by LoggerNet but no reply. Also, if I connect using PuTTY, sending multiple CR characters does not result in the CR3000> prompt.
A similar crash occurred about a month ago and we could restart the system by cycling power to all three data loggers. Unfortunately, there will be no person at the site until February, so this method cannot be used to gain back communications.
In my opinion a communication system software should reset itself automatically if there is a connection that was not properly closed and there is no activity for a settable timeout period.
(1) What can I do in this situation to gain back communication?
(2) What should I do so that this does not happen again in the future?
Thanks in advance for any advice.
Frank