Checking the SPI 3 for correct operation
18
Trebing & Himstedt | SPI 3 | MODBUS RTU
2.
Load function block in an existing project:
– Start PLC programming software.
– Open the example project.
– Copy the FB 127 into your PLC program. Enter FB command parameters (see
»Using data channel with »MODBUS_ Kanal« module and FB 127« on
page 20).
– Execute further steps for your PLC program (integrate SPI 3 in hardware catalog,
select modules, adjust SPI 3-specific parameters, create DB, command FB etc.).
– Proceed further as described in the handbook or online support of the PLC
programming software.
The SPI 3 is ready for use after installation of the function block.
Checking the SPI 3 for correct operation
Several checks should be run before using the SPI 3 for data transfer.
Checking SPI 3 power feed
– At this stage, do not attach either the PROFIBUS interface or the serial interface.
– Switch on the power feed for the SPI 3.
The RUN LED should light continuously. If this is not the case, there is a fault in the
24 V power feed. Refer to »Error diagnosis and remedies« on page 25 for details of
how to locate the fault.
Checking PROFIBUS communication
– Connect up the PROFIBUS interface cable.
– Switch on the power feed for the SPI 3 (RUN-LED lights up).
– Start the DP master which has previously been configured for the SPI 3.
The PB LED should light continuously. If this is not the case, there is an error in the
PROFIBUS communication. Refer to »Error diagnosis and remedies« on page 25 for
details of how to locate the fault.
Checking serial interface communication
– Connect up the PROFIBUS interface cable and the serial interface cable.
– Switch on the power feed for the SPI 3 (RUN-LED lights up).
– Start the DP master which has previously been configured for the SPI 3 (PB-LED
lights up).
The RUN LED should light continuously. If it does not light, or it only flashes, there is
