S7200 Smart can't Access Timer and Counter

[e70123456]

Expert:
It is normal to read and write other types of registers(V,M,Q,I) now. I use Step7-Micro download plc program, The plc is running normally.

      Then, i try to read T37(my plc program used it), the respond is"

Connected to PLC.
Error: Received error from PLC: Accessing object not allowed.
Connection closed."

       C# caller is "int timer = (int)plc.Read(DataType.Timer, 37,  0,  VarType.Timer,  1);"

I don't know whether parameters configuration is correct，and other error？

[e70123456]

the other caller is “byte[] TimerBytes = plc.ReadBytes(DataType.Timer, 37, 0, 1);” , it has same respond.
This is an explanation of it in the help document: