Remote test of IOlog modules
Users and developers can test IOlog data acquisition modules thanks to a test system, which can be accessed at address iolog.sielcosistemi.com using Modbus TCP protocol on port 502.
By this way you can directly communicate with remote IOlog modules using your own supervisory software or your own PLC. You can also download the software Winlog Evo and run the project Circuit Demo.
System is designed to provide feedback to the user, so you can verify that commands sent have been executed. Digital outputs of module SS3130 are wired to the digital inputs of SS3148; analog outputs of module SS3024 are wired to the analog inputs of SS3017-I (see the figure below). Furthermore four thermocouple sensors, which measure the environmental temperature, are connected to module SS3016.
Addressing of modules and variables
For each of the modules of the test system, the following table provides a description, the Modbus address of the device, and the links to download the datasheet and the user guide.
| Model | Description | Modbus address | Datasheet | User guide |
| SS3580 MBTCP | Converter from Modbus TCP over Ethernet to Modbus RTU over RS485 | - |
 EN  IT |
|
| SS3130 | Digital module with 4 digital inputs and 4 relay outputs | 1 |
EN IT |
EN IT |
| SS3148 | Digital module with 12 digital inputs | 2 |
EN IT |
EN IT |
| SS3024 | Analog module with 4 voltage or current outputs | 3 |
EN IT |
EN IT |
| SS3017-I | Analog module with 8 current inputs | 4 |
EN IT |
EN IT |
| SS3016 | Analog module with 4 thermocouple inputs | 5 |
EN IT |
EN IT |
The user guide provides the “Modbus map” of the device, that is a table which assigns the proper Modbus address to every data that can be read or written. There are two types of data:
- register: 2 bytes long (16 bit word), it is used to represent analog inputs, analog outputs, or numeric variables;
- coil: a single bit, used to represent state of digital inputs (contacts), digital outputs (relais), or logical information (alarms, flags, etc.)
A register can also be used to group several coils. For example, the digital inputs of a device can be read all together as a single register (16-bit word), where each bit corresponds to a coil.