Description of Controls
Page 55 of 90 057-233 ISSUE: 1
4.2.8.2 RS485 SERIAL PORT
NOTE: Factory Default settings are for the RS485 port to operate at 19200 baud, modbus
slave address 10.
This section is included to give information about the currently selected serial port
The items displayed on this pagel change depending upon configuration of the module. Refer to the
system supplier for further details.
Module RS485 Port Configured For Connection to A Modbus Master
The modules operate as a modbus RTU slave device.
In a modbus system, there is only one Master, typically a PLC,
HMI system or PC SCADA system.
This master requests for information from the modbus slave
(The 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 data
link.
The factory settings are for the module to
communicate at 19200 baud, modbus slave
address 10.
‘Master inactivity timeout’ must be set to at least
twice the value of the system scan time. For
example if a modbus master PLC requests data
from the module once per second, the timeout
must be set to at least 2 seconds.
The DSE MODBUS document containing register mappings inside the DSE module is available upon
request from support@deepseaplc.com. Email the request along with the serial number of the DSE
module to ensure the correct information is sent.
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)
ControlledShutdown=(ReadRegister(10,0306,1) >> 10) & 1): reads (hex) 0306 and looks at
bit 11 (Controlled Shutdown alarm present)
ControlMode=ReadRegister(10,0304,2): reads (hex) register 0304 (control mode).
To Next Page
Loading...