Operating Instructions

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Siemens Modbus för SOC7-128, slave mode SE1Z5996en7

Building Technologies 3 Connection and Configuration 2015-08-26

3.4 Connection via ethernet network

To connect to the system unit SOC7-128 via a Ethernet network a gateway must be

used at the SOC7-128. If the master cannot integrate Modbus/TCP a gateway must

also be installed at that side. The picture bellows shows a topology where a gateway

has been installed also at the master side.

For correct configuration of the gateways, please refer to the specific gateway manuals.

A special modbus/TCP – modbus/serial gateway is recommended, do not use a

standard terminal server.

Tip: Modbus/RTU uses a timeout of 3,5 character instead of a stop character to define

end of message. Communicating over a large network eg. Internet it can cause

problems due to the nature of TCP/IP. It can be a good idea to use modbus/ASCII on

the master side (and only on the master side) when using a gateway. This can only be

realized if a modbus gateway is used rather than a standard terminal server. If the

master only can use Modbus/RTU correct message and character timeouts should be

configured.

3.5 Configure

Default communication settings are : slave address 2, 9600 baud, 8 databits, 1 stopbit,

parity none. Follow the instructions below to configure RS485 and Modbus.

1. Commissioning unit with all settings according to the manual G5996sv4_SOC7-

128sv.pdf before starting to configure Modbus.

Navigate to menu “Settings – Modbus”.

3. Set the slave address for the device. (1-247, Must be unique).

4. Set Baudrate for RS485 (300-19200)

5. Set Parity for RS485 (None, Even, Odd)

6. Set number of Stopbit for RS485 (1 or 2)

7. Push “ESC” to return to main menu.