DSE5510 genset controller communication with MODBUS poll software

[zeeshan ahmed]

Hi all!

I m currently working on communication of DSE5510 with MODBUS poll software . But i m getting READ ERROR and some times TIMEOUT ERROR. I want to read generator and engine parameters in MODBUS poll. Kindly help me in this matter ASAP.

Thanks and Best regards,

Zeeshan

[merryengineer]

Have you reviews the manual on the subject?

Such as:

NOTE: - The RS485 system will comprise of one MODBUS master (typically a PC) and
up to 31 MODBUS slaves. The 5510 modules are always MODBUS slave devices. To ensure
correct operation a suitable 120W terminal resistor must be fitted to each end of the RS485
connection bus

.
and:

Caution! - The A and B lines of the 485 network should be terminated at each end with a
120W resistor.
Some RS485 devices (PC cards in particular) are already fitted with a terminating resistor.
However if they are not installed as an �end of line� device then such terminating resistors
must be removed. Other RS485 devices may be fitted with a �switchable� resistor, again this
must be switched out if the device is not installed as an �end of line� device.

and

CAUTION! -. RS485 cabling must be 120W impedance cable, specified for use with
RS485. 120W terminating resistors must be fitted to the first and last devices on the bus.
Some PC RS485 cards are already fitted with this resistor, and in this case should not be
fitted externally. If in doubt, consult the supplier of your PC RS485 card.
If the 5510 controller is the �last� device on the bus, then it�s RS485 connection must be
suitably terminated with a 120W resistor as detailed in the specification laid out in the RS485
standard.
Recommended cable BELDEN 9841 120W RS485 cable.
DSE part number 016-030.

The RS485 output uses Modbus� communications protocol. This uses a master-slave technique to
communicate. Only the Master can initiate a packet transaction, called a �query�. When appropriate
the slave (5510 Module) responds to the query and provides the information requested by the
master.
All supported data can be read and written as specified in the register table (documentation is
available from Deep Sea Electronics Plc.).
When the 5510 Module receives a query it will respond by either supplying the requested register
data or performing the requested action. A slave device (the 5510 module) will never initiate
communications on the Modbus� link. The 5510 can only be configured as a slave device. The
Master can only query individual slaves. Refer to the Modbus� protocol document for more details.

Its also worth checking if you have:

1) The correct DSE 5110 module. Some have RS 485, others only RS232.
2) Have you tried connecting with link 5000 (free software from DSE) does this work?