I have 25 T100MD-888+ plc's with MX-RTC and R48 Low Temperature Chipset options in operation some approaching 2 years old. Recently I have had two units returned for repair, ( May 9th and May 24th), both units in the field for about a year. When connecting Trilogi to the units I got a " PLC's program failed Checksum Test ( corrupted). With online monitoring, I could see all the inputs were functioning ( I have an Encoder input, and input states were changing on the view display )and outputs could be controlled, 16x2 LCD display had cursor blinking in upper left corner. Re programming restored operation, but the data in the DM
- battery backed memory was lost, whether I reset the PLC at programming, or not. ( I thought I could possibly re-program, but not reset, and still retrieve data from the DM
- memeory. I use a portion of the DM
- memeory as s data logger, logging dates of use.
The program does not use the EEPROM as any memory storage other than the program, so the read operation is the only function used when starting up.
The system R48 operates in a mobile environment on 12 vdc. The input is configured as indicated in the installation manual, with a series diode, and a 10,000 uf cap across the input power lines. The inputs are one incremental encoder, a 4 key keypad, reading Four 0-20 ma currrent loops. Outputs to a 16x2 LCD, and two alarms, one LED bank, and one audible Piezio horn.
Any assistance to identify the problem would be appreciated.