Siemens Simatic RTU303xC Series Operating Instructions Manual page 207

● Device
From the list, select the device to which the tag is assigned.
● Tag type
Assign the tags to one of the following types:
– Digital input
– Counter input
– Analog input
Modbus
Configure the address and data parameters of the tag here.
● Slave address (UID)
Display of the address of the Modbus slave defined by the device selection (above).
● Function code
Function code according to Modbus specification.
The following is supported for digital inputs:
– 0x01 – Read Coils
– 0x02 – Read Discrete Inputs
The RTU always reads only one bit here.
The following is supported for counter inputs and analog inputs:
– 0x03 – Read Holding Registers
– 0x04 – Read Input Registers
Only one register is read per function code. Size and interpretation (16-bit or 32-bit) can
be selected via the "Data type - Endianness" drop-down list.
● Data start address
Here, you configure the coil or register address in your Modbus slave.
The address to be read corresponds to the value "Data start address" + 1.
Refer to the descriptions of your connected sensors for the addresses.
Enter the address in decimal or hexadecimal form. The corresponding value is displayed
in the other format.
Value range (hex): 0x0000 .. 0xFFFF
RTU303xC
Operating Instructions, 06/2019, C79000-G8976-C382-06
The tag type is intended for digital signals.
The tag type is intended for counter inputs.
Formats of the tags: Integer without sign (32 bits)
The tag type is intended for analog signals
Configuration (WBM)
4.20 Extension board
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