S7-200 CPU and OP 27 HMI

[mitsibushiman 0]

Good day all!. I've a little problem with a siemens controller. It may seem like a daft question, so I'll apologise in advance!. The settup is a S7-224 CPU with various expansion I/O which is connected via the S7 CPU Serial port to a Siemens OP27 HMI. I've had a brief look at the setup, I'm due to go onsite tomorrow to investigate an intermittent fault that appears from time to time. I'm not very familiar with S7, although I have Microwin and Protool. I have a siemens PPI cable to communicate with the CPU. Generally when I do this kind of work on a Mitsubishi I like to communicate "transparently" through the HMI to the CPU so I can "see" the information being written to the CPU from the HMI. Is this possible with the siemens OP range of HMI's ??? If so how and what does one need to be able to do it???. Any help or advice greatly appreciated. Cheers Quick Edit.....I need to be able to do this as from what I've seen the HMI is constantly transferring data to the CPU in word format which are then written into bits in the program that controls the operation of the machine. Edited 9 Sep 2009 by mitsibushiman