Siemens S7 - Troubleshooting
Troubleshooting of Siemens S7 instances and items
This article will describe some of the most common faults encountered when trying to connect to Siemens S7 PLCs. All the various error messages is also explained here.
Caution
Items reads in blocks and if one of the item have an error this will affect all of the other items that are from the same DB.
Error messages
Both instance and items can have errors. These are showed on the portal and the following sections describes the error and how to solve them.
Instance
| Error message | Description | Solution |
|---|---|---|
| Unreachable peer |
The IP address is not responding. | Check the IP address and that you can ping it. Ensure that SIA is in the same network as the PLC |
| Connection timed out |
The IP address is accessible but not receiving any response. | Check that the rack and slot are correct set. |
Item
| Error message | Description | Solution |
|---|---|---|
| Address out of range | Reading from an offset that is outside of the memory in the PLC. | Check that the offset exists in the PLC. This message will show when you are trying to access and offset that is outside of what the PLC contains. |
| Function refused by CPU |
The PUT & GET function was refused by the PLC | Enabled PUT & GET in the PLC. For more information on how to this check Prepare PLC in TIA portal for external communication |
| Item not available | The items you are trying to read is not available in the PLC. Either it is outside of range or you cannot access it. |
|
| Invalid memory area | The memory area you are trying to read from cannot be accessed or identified. |