Repair GE-Emerson Series 90-30 IC693ACC306 EPROM Chips

The GE-Emerson Series 90-30 IC693ACC306 EPROM Chips allow for additional program integrity and/or operation of the PLC without a battery. The chips can be installed in a spare socket (labeled PROGRAM PROM) on the Model 311 backplane or in a socket on the Model 331 CPU module. EPROMS can be read when installed in the PLC, however they must be written to using an external PROM burning device. Non-removable flash memory performs this function on the Model 340, 341, and 351 CPUs. 

A typical scheme for using these devices is to develop programs using an EEPROM. When the program in RAM has been developed and debugged, it is saved to EEPROM. The EEPROM can then be removed from the PLC and used as a master to make backup or multiple copies of the program to EPROM memory. The EPROM can then be installed in the socket provided in the CPU and used as a non-volatile memory for battery-less operation, or to run the same program in multiple PLCs. The Model 331 CPU has a jumper (JP1) located next to the EEPROM/EPROM socket to let you select between EEPROM or EPROM.