Pixsys EPL101, Руководство пользователя

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not guaranteed, therefore it is recommended to avoid continuous
writings in this area.
1.7.12 Memory area MMC
MMC area is the optional external memory which can be used to save big
amounts of data which must be stored even by lack of power supply.
Memory is Eeprom, therefore access to this area is slower than access to
area V and SM. PLC does not check integrity of data saved in this area.
This area is divided in words (0
÷
32767) and can be entered also by
Modbus protocol.
N.B.: MMC memory allows a max number of writigs for each single
location (1000000 are guaranteed). Above this number, data are not
guaranteed, therefore it is recommended to avoid continuous writings
in this area.
1.7.13 Memory area COMx_SEND
Memory area COMx_SEND are used to load data which will be sent to the
relevant serial port. They are used only in free-port mode. In standard
mode these areas are handled with the selected communication protocol.
These ares are divided in byte (8 bit).
1.7.14 Memory area COMx_RECEIVE and IR_RECEIVE
Memory areas COMx_RECEIVE and IR_RECEIVE are used to save data
received by the relevant serial port. They are used only in mode free-port.
In standard mode these areas are handled with the selected
communication protocol.
These ares are divided in byte (8 bit).
1.8 Protocol Modbus RTU slave
EPL101 is conceived for the use with SCADA systems or Operator panels
via Modbus protocol RTU. Serial communication enables reading and
modifying of data on available memory areas, entering and visualizing any
data concerning the PLC. Module PL250A is provided with 2 serial
communication ports which are enabled to operate as slaves with
MODBUS protocol:
•
COM1 - RS485 available on connector plug-8 and on pins
•
COM2 - RS232 available on connector plug-8