DEEP SEA ELECTRONICS DSE8610 MKII Operator's Manual page 124

Connected to An RS232 MODBUS Master
NOTE: The MODBUS Master can be another DSE module communicating through its PLC.
For further details see section entitled RS232 Used For PLC Communication elsewhere in this
document.
The modules operate as a MODBUS RTU slave device. In a MODBUS system, there is only one
Master, typically a PLC, HMI system, PC SCADA system, or another DSE module using its PLC
Comms.
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 DSE MODBUS document containing register mappings inside the DSE module is available upon
request from support@deepseaelectronics.com. Email the request along with the serial number of
the DSE module to ensure the correct information is sent.
RS232 MODBUS RTU Diagnostics
RS232 MODBUS RTU diagnostic screens are included; press the Scroll Down
viewing the RS232 Serial Port instruments to cycle to the available screens. If experiencing RS232
MODBUS RTU communication problems, this information aids troubleshooting.
RS232
Link Quality
RX Rate
Lost Rate
057-254 ISSUE: 10
Description of Controls
Shows the state of the RS232 communication lines.
98 %
These can help diagnose connection problems.
49
1
Link Quality: The quality of the RS232 connection
RX Rate: The number of received message during the
packet timeout
Lost Rate: The number of messages that are discarded
(invalid messages)
Page 124 of 246
The factory settings are for the module to
communicate at 115200 baud, MODBUS slave
address 10.
To use the RS232 port, ensure that 'port
usage' is correctly set using the DSE
Configuration Suite Software.
'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 module once per
second, the timeout should be set to at least 2
seconds
button when