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Getting 'Read not completed' and 'Write not completed' errors while trying to read from Softing.OPC.S7 - by: djorsher

Hi,

I'm trying to read and write to a Softing S7 server running on localhost, but getting errors.

I'm using OpcLabs.EasyOpc.DataAccess.EasyDAClient via the win32com client for Python.

I've installed on my machine (Windows 7) both the Softing S7 server and the Softing Demo Server.

When reading and writing from/to the Demo Server - it works.

The commands I'm issuing are:
client = win32com.client.Dispatch('OpcLabs.EasyOpc.DataAccess.EasyDAClient')
client.WriteItemValue('localhost','Softing.OPC.S7.DA.1', 'NodeB/Test1', 1)
client.ReadItemValue('localhost','Softing.OPC.S7.DA.1','NodeB/Test1')


I'm getting these errors:

1. Read not completed. This error indicates that it could not be verified that the requested read operation was completed during the timeout period. It is possible that the read operation will actually succeed or fail, but later. Increase the timeout period if you want to obtain positive or negative indication of the operation outcome. Other reason for this error may be that under heavy loads, topic request or response queue is overflowing. Check the event log for queue overflow errors (if event logging is supported by the product and enabled).

2. Write not completed. This error indicates that it could not be verified that the requested write operation was completed during the timeout period. It is possible that the write operation will actually succeed or fail, but later. Increase the timeout period if you want to obtain positive or negative indication of the operation outcome. Other reason for this error may be that under heavy loads, topic request or response queue is overflowing. Check the event log for queue overflow errors (if event logging is supported by the product and enabled).

After issuing the write operation, the item value is set to 1, but it hangs for a while, and then I'm getting this error.

Any help would be appreciated.

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