ProSoft Technology 5202-DFNT-MCM4 - Manual (Page 14)

MCM ♦ ProLinx Gateway Functional Overview
Modbus Master/Slave Driver Manual
Page 14 of 80
ProSoft Technology, Inc.
October 16, 2009
2.4 Module Internal Database
The internal gateway database is central to the functionality of the gateway. This
database is shared between all the ports on the gateway This permits data from
devices on one communication network port to be viewed and controlled by
devices on another port or network.
Other ProLinx
Protocol
Driver
Modbus
Slave
Driver
Modbus
Master
Driver
ProLinx
Communication
Gateways
Internal
Database
(Up to 4000 regs)
Other ProLinx
Protocol
Driver
Modbus
Slave
Driver
Modbus
Master
Driver
ProLinx
Communication
Gateways
Internal
Database
The Master driver uses the database in two ways:
ƒ A read command issued to a slave device by the Master driver will return the
slave data into the internal database.
ƒ A write command issued to a slave device by the Master driver uses the data
in the internal database as the source data to send to the slave.
The slave driver allows external Master devices to access the database, reading
data from the database or writing data to the database. External Modbus Master
devices can monitor and control data in this database through any port
configured as a slave.
Status and error data from the slave and Master ports generated by the gateway
can be mapped into the internal database, where it can be retrieved by either
protocol driver.