Description
DS200TCEAG1B Technical Specifications
Manufacturer GE General Electric
Part Number DS200TCEAG1B
Product Type Emergency Over Speed Board
Series Mark V
There are mainly two kinds of memories: one is read/write random access memory RAM, and the other is read-only memory ROM, PROM, EPROM and EEPROM. In PLC, memory is mainly used to store system program, user program and working data.
The system program is prepared by the manufacturer of PLC, which is related to the hardware composition of PLC. It completes the functions of system diagnosis, command interpretation, function subprogram call management, logic operation, communication and various parameter settings, and provides a platform for PLC operation. The system program is related to the performance of the PLC and will not change during the use of the PLC, so it is directly solidified in the ROM, PROM or EPROM by the manufacturer, and users cannot access and modify it.
The user program is an application program that depends on the control object of PLC and is compiled by the user according to the control requirements of the object production process. In order to facilitate reading, inspection and modification, user programs are generally stored in CMOS static RAM, and lithium batteries are used as backup power to ensure that information will not be lost in case of power failure. In order to prevent the program in RAM from being damaged by interference, when the user program runs normally and does not need to be changed, it can be fixed in the read-only memory EPROM. Nowadays, many PLCs directly use EEPROM as user memory.