10 modbus/tcp, 11 modbus-rtu protocol, 10 modbus/tcp 3.11 modbus-rtu protocol – Rice Lake Signal Conditioning Transmitter/Indicators User Manual

Page 50: Section 3.11)

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46 SCT Weight Transmitter Operator’s Manual

3.10 Modbus/TCP

The instrument works as a slave in a Modbus/TCP network. TLBMODBUSTCP instrument is configured with

DHCP (default). IP Address can be automatically assigned by DHCP or manually via Telnet. To manually set the

IP address via PC, type "telnet <ipaddress> 9999" and press Enter to confirm. The following screen appears:

1. Type “1” if you want to manually configure IP Address, Default Gateway Address and Netmask.
2. Then type “S” to save.

Modbus/TCP commands and registers of TLBMODBUS/TCP are the same as ModbusRTU protocol

(see Section 3.11).

3.11 Modbus-RTU Protocol

The MODBUS-RTU protocol enables management of the reading and writing of the registers listed here below

according to the specifications contained in the reference document for this standard Modicon PI-MBUS-300.
To select the communication with MODBUS-RTU, refer to Section 2.9 on page 24.
When specifically indicated certain data will be written directly to EEPROM type memories. This memory has a

limited number of writing operations (100.000), therefore unnecessary operations at said locations must be

avoided. The instrument, in any case, ensures that no writing occurs if the value to be stored is equal to the stored

value.
The numerical data listed below are expressed in decimal notation, or hexadecimal notation if preceded by 0x.

Modbus-RTU Data Format

The data received and transmitted via MODBUS-RTU protocol have the following characteristics:

- 1 start bit
- 8 data bits, least significant bit sent first
- Instrument settable parity bit
- Instrument settable stop bit

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