Datatype compatibility between PLC and Python

[rexxon]

Hey everybody!

I have a short question regarding the datatypes compability between PLC and python. Is there any way to write non-boolean PLC-datatypes with python, for example floats etc.?

For example with the following two GVL variables:

The way of writing variables like boolean ones, does not work for float or integer values:

Neither with a typecast, nor without:

I always get a runtime error:

Does anybody know, which types are compatible? And do you furthermore know, how to get print() or stdout working in the script engine?

Kind regards

[CodeShepherd · Accepted solution]

I did some tests and got it to run with the write_json only up to now. See my code below.

EDIT: Only 64bit signed numbers can be written with "datalayer.write" at the moment. See all working examples below.

#from ctrlxpy import datalayer
import json

#test with bool variable
MyBool = datalayer.read("plc/app/Application/sym/GVL_Test/bTest")
MyBool = not MyBool
datalayer.write("plc/app/Application/sym/GVL_Test/bTest",MyBool)

#test with string variable
MyString = datalayer.read("plc/app/Application/sym/GVL_Test/sTest")
MyString = 'nothing'
datalayer.write("plc/app/Application/sym/GVL_Test/sTest",MyString)

#test with wide string variable
MywString = datalayer.read("plc/app/Application/sym/GVL_Test/wsTest")
MywString = 'totally nothing'
datalayer.write("plc/app/Application/sym/GVL_Test/wsTest",MywString)

#test with long integer variable
MylInt = datalayer.read("plc/app/Application/sym/GVL_Test/liTest")
MylInt += 1
datalayer.write("plc/app/Application/sym/GVL_Test/liTest",MylInt)
datalayer.write("plc/app/Application/sym/GVL_Test/liTest",42)

#test with long real variable
MylReal = datalayer.read("plc/app/Application/sym/GVL_Test/lrTest")
MylReal += 1
datalayer.write("plc/app/Application/sym/GVL_Test/lrTest",MylReal)
datalayer.write("plc/app/Application/sym/GVL_Test/lrTest",4242424242.42)

#read different types
MysInt = datalayer.read("plc/app/Application/sym/GVL_Test/siTest")
MyusInt = datalayer.read("plc/app/Application/sym/GVL_Test/usiTest")
MyInt = datalayer.read("plc/app/Application/sym/GVL_Test/iTest")
MydInt = datalayer.read("plc/app/Application/sym/GVL_Test/diTest")
MyudInt = datalayer.read("plc/app/Application/sym/GVL_Test/udiTest")
MyulInt = datalayer.read("plc/app/Application/sym/GVL_Test/uliTest")
MyReal = datalayer.read("plc/app/Application/sym/GVL_Test/rTest")

MyJSON_sInt = datalayer.read_json("plc/app/Application/sym/GVL_Test/siTest")
MyJSON_usInt = datalayer.read_json("plc/app/Application/sym/GVL_Test/usiTest")
MyJSON_bool = datalayer.read_json("plc/app/Application/sym/GVL_Test/bTest")
MyJSON_string = datalayer.read_json("plc/app/Application/sym/GVL_Test/sTest")
MyJSON_wstring = datalayer.read_json("plc/app/Application/sym/GVL_Test/wsTest")
MyJSON_int = datalayer.read_json("plc/app/Application/sym/GVL_Test/iTest")
MyJSON_dint = datalayer.read_json("plc/app/Application/sym/GVL_Test/diTest")
MyJSON_udint = datalayer.read_json("plc/app/Application/sym/GVL_Test/udiTest")
MyJSON_lint = datalayer.read_json("plc/app/Application/sym/GVL_Test/liTest")
MyJSON_ulint = datalayer.read_json("plc/app/Application/sym/GVL_Test/uliTest")
MyJSON_real = datalayer.read_json("plc/app/Application/sym/GVL_Test/rTest")
MyJSON_lreal = datalayer.read_json("plc/app/Application/sym/GVL_Test/lrTest")

#Not working
#datalayer.write("plc/app/Application/sym/GVL_Test/siTest",MysInt)
#datalayer.write("plc/app/Application/sym/GVL_Test/usiTest",MyusInt)
#datalayer.write("plc/app/Application/sym/GVL_Test/iTest",MyInt)
#datalayer.write("plc/app/Application/sym/GVL_Test/iTest",MydInt)
#datalayer.write("plc/app/Application/sym/GVL_Test/rTest",MyudInt)
#datalayer.write("plc/app/Application/sym/GVL_Test/rTest",MyulInt)
#datalayer.write("plc/app/Application/sym/GVL_Test/rTest",Myreal)

#Insert variable in string
MyInt += 1
datalayer.write_json("plc/app/Application/sym/GVL_Test/iTest",'{"type":"int16","value":'+str(MyInt)+'}')

#create string by hand
MyJSON2 = '{"type":"int16","value":43}'
datalayer.write_json("plc/app/Application/sym/GVL_Test/iTest",MyJSON2)

#read out and manipulate JSON object
MyJSON_string = datalayer.read_json("plc/app/Application/sym/GVL_Test/iTest") #{\n"type": "int16",\n"value": 42\n}
datalayer.write_json("plc/app/Application/sym/GVL_Test/iTest",MyJSON_string)
MyJSON_object = json.loads(MyJSON_string)
MyJSON_object["value"] += 1
MyJSON_string2 = json.dumps(MyJSON_object)
datalayer.write_json("plc/app/Application/sym/GVL_Test/iTest",MyJSON_string2)