system.opc.writeValue
This function is used in Python Scripting.
Description​
Writes a value directly through an OPC server connection synchronously. Will return an OPC-UA status code object. You can quickly check if the write succeeded by calling isGood() on the return value from this function.
Client Permission Restrictions​
Permission Type: OPC Server Management
Client access to this scripting function is blocked to users that do not meet the role/zone requirements for the above permission type. This function is unaffected when run in the Gateway scope.
Syntax​
system.opc.writeValue(opcServer, itemPath, value)
Parameters​
Type | Parameter | Description |
---|---|---|
String | opcServer | The name of the OPC server connection in which the item resides. |
String | itemPath | The item path, or address, to write to. |
Object | value | The value to write to the OPC item. |
Returns​
Quality - The status of the write. Use returnValue.isGood() to check if the write succeeded. Refer to the list of writeValue objects.
Scope​
Gateway, Vision Client, Perspective Session
Code Examples​
# This example will write to an OPC Tag that is on a provider called SLCSim
# Declare the server name
server = "Ignition OPC UA Server"
# Declare the Tag path
path = "[SLCSim]_Meta:N7/N7:0"
# Declare the system function parameters
oldQualifiedValue = system.opc.readValue(server, path)
newValue = oldQualifiedValue.getValue() + 1
# Call the system function and print out results
returnQuality = system.opc.writeValue(server, path, newValue)
if returnQuality.isGood():
print "Write was successful"
else:
print "Write failed"
Keywords​
system opc writeValue, opc.writeValue