115
15. Modbus communication
The Modbus communication is a serial interface used for standard RS-485 communication.
The communication with the instrument supported with the Modbus communication can be done
without program.
- Modbus is a registered trademark of the Modicon Inc.
The data communication with CSD-903 does not have to make the program of the communication
protocol because it can be operated with the mapped memory operation in the table below.
When using the Modbus communication, set as shown in [14-3.Item of RS-485 communication
setting] as below.
Standard RS-485 should be used as hardware of communication.
Moreover, as for decimal point addition, the terminator, and communication delay time, the setting
will become in VALID since they have no relation with the Modbus operation.
Item Set value
Operation mode Modbus
Baud rate Make selection from 1 200 bps,2 400 bps,4 800 bps,
9 600 bps, 19 200 bps and 38 400 bps.
Data bit length 8 bit
Parity bit Selection from no parity, even parity, and odd parity
Stop bit Select from 1 bit and 2 bit.
Address
Select one from 0 to 31.
However, 0 is the broadcast address
・ The standard RS-485 interface and Modbus communication cannot be used when the optional
communication either of RS-232C, RS-422, RS-485 or CC-Link is equipped with Communication and
Modbus communication, and optional RS-232C communication, and RS-422 communication, and
RS-485 communication, and CC-Link communications are not interlocked each other.
・ Function F-45 shall be applied with more than the value of [01].
・ Please set the delay time of 5 ms or more to host side.
・ To use the brand number in Modbus communication holding register [53249], set function F-51 to
[2]. To use the F-52 brand selection settings [57447 to 57448], set function F-51 to [0].
Output coil (Bit, Reading out/Writing, Reference 0)
Address Data name Address Data name
1 ZERO 13 UNUSED
2 ZERO CLEAR 14 EMERGENCY STOP
3 TARE 15 UNUSED
4 TARE CLEAR 16 FORCED BATCH FINISH
5 FLOW START 17 UNUSED
6 UNUSED 18 FORCED DISCHARGE FINISH
7 DISCHARGE START 19 ERROR RESET
8 UNUSED 20 CHANGE OF HOLD/HOLD RELEASE
9 MANUAL FREE FALL COMPENSATION 21 PRINT COMMAND
10 ACCUMULATION COMMAND 22 GROSS/NET CHANGEOVER
11 CLEAR THE LAST ACCUMULATED DATA 23 ALL BRAND ACCUMULATION CLEAR
12 UNUSED 24 UNUSED
To Next Page
Loading...
