Winco DSE7300 Series User Manual
Page 64
DSE Model 7000 Series Control and Instrumentation System Operators Manual
64
Part No. 057-074 7000 Series OPERATING MANUAL ISSUE 5 15/10/2009 ADM
Example 4 - Module RS485 port configured for connection to a
modbus master.
DSE7300 series modules operate as a modbus RTU slave device.
In a modbus system there can be only one Master, typically a PLC, HMI system or PC SCADA system.
This master requests for information from the modbus slave (DSE7300 series module) and may (in control
systems) also send request to change operating modes etc. Unless the Master makes a request, the slave is ‘quiet’
on the datalink.
The factory settings are for the module to communicate at 19200 baud, modbus slave address 10.
To use the RS485 port, ensure that ‘port usage’ is correctly set using the DSE Configuration Suite Software.
Required settings are shown below.
‘Master inactivity timeout’ should be set to at least twice the value of the system scan time. For example if a modbus
master PLC requests data from the DSE7300 modbus slave once per second, the timeout should be set to at least
2 seconds.
The DSE Modbus Gencomm document containing register mappings inside the DSE module is available upon
request from
. Email your request along with the serial number of your DSE module to
ensure the correct information is sent to you.
Typical requests (using Pseudo code)
BatteryVoltage=ReadRegister(10,0405,1)
: reads register (hex) 0405 as a single register (battery volts) from slave
address 10.
WriteRegister(10,1008,2,35701, 65535-35701)
: Puts the module into AUTO mode by writing to (hex) register 1008, the
values 35701 (auto mode) and register 1009 the value 65535-35701 (the bitwise opposite of auto mode)
Shutdown=(ReadRegister(10,0306,1) >> 12) & 1)
: reads (hex) 0306 and looks at bit 13 (shutdown alarm present)
Warning=(ReadRegister(10,0306,1) >> 11) & 1)
: reads (hex) 0306 and looks at bit 12 (Warning alarm present)
ElectricalTrip=(ReadRegister(10,0306,1) >> 10) & 1)
: reads (hex) 0306 and looks at bit 11 (Electrical Trip alarm
present)
ControlMode=ReadRegister(10,0304,2);
reads (hex) register 0304 (control mode).