System registers are used to set values (parameters) which determine operation ranges and functions used. Set values based on the use and specifications of your program. There is no need to set system registers for functions which will not be used.
Not all system registers are available for all PLC types. Please see the system register tables for a list of system registers for each PLC type.
Memory size
Size of the memory area for the user program.Hold on/off
Use these system registers to specify the hold area start addresses for flags and registers. Hold areas are not cleared to 0 when the PLC is switched to PROG mode or when the power is turned off. The memory area for timer flags and counter flags is partitioned using system register no. 5. Specify the start address for the counter flags.
Act on error
Set the operation mode to be chosen after errors such as an operation error, a battery error, or an I/O verification error.
Time settings
Set the waiting time before an error is output. You can also specify a constant scan time.
MEWNET-F
Set the PLC start mode and timeout when MEWNET-F slave stations are connected.
PLC link
These settings are for using link flags and link registers in MEWNET-W0 PLC link communication. Note that PLC Link is not the default setting.
PROFIBUS/MEWNET-H
Set the data size to be processed during one scan.
High-speed counters, pulse outputs, interrupt inputs, pulse-catch inputs
When using the high-speed counter function, pulse catch function or interrupt function, set the operation mode and the input number to be used for the function.
Time constants of inputs
Set a time constant for the CPU inputs. These time constants can be useful to negate the effects of noise or bouncing, e.g. for a switching device.
TOOL port, COM port
Set these registers when the TOOL port and COM ports 1 and 2 ports are to be used for MEWTOCOL-COM Master/Slave connections, program controlled communication, PLC link, and modem communication. Note that the default setting is MEWTOCOL-COM Master/Slave.