Skip to Content

Register Login

Industry Online Support

Technical Forum

Navigation

CPU 946/947 with AS-511 protocol and OP

Created by: Schmiermerker at: 1/23/2008 2:24 AM (4 Replies)

Rating (0)

Thanks 0

5 Entries

1/23/2008 2:24 AM	Rate (0)
Schmiermerker Posts: 2 Rating: (0)	Hello, I have a problem connecting an operator panel with a PLC using the AS-511 protocol. Operator Panel: non-Siemens (not very happy about it, but I have no choice) PLC: S5-155H with CPU's 946/947 (this is the plc in the factory, can't use it much for testing) Connection with one datablock (DB199), length = 255 words. Cable: tty I also have the following cpu's available for testing: CPU 948 and CPU 928B According to the manual of the operator panel, I only need to have a datablock in the PLC, no other blocks necessary for the communication. My problem is this: I can make everything work with the CPU 928B. The PLC only contains OB1 (empty) and DB199 (lenght 255 words). Communication works as it should be on the 928B. If I use the CPU948, also with OB1 (empty) and DB199 (255 words) it doesn't work. I use the same cable for connecting the OP with the PLC. With the CPU 946/947 I have the same problem as with the CPU948, it doesn't work at all. When I make the DB199 slightly shorter (254 words) than configured in the OP (255 words), I get an error message on the OP (which is correct of course). This works on all CPU's. So it looks like the OP can see the datablock in the CPU948 and in the CPU946/947 (because it gives an error when it's too short), but for some reason it can't communicate with it. Does anybody know if there are differences in the AS-511 protocol on the CPU948 and CPU946/947 compared to the CPU928B? What could be the reason the AS-511 communication works with CPU928B and not with CPU948 or CPU946/947? Thanks in advance.
Schmiermerker Posts: 2 Rating: (0)
Suggestion To thank Quote Answer

1/23/2008 3:06 AM	Rate (0)
Sigma Advanced Member Joined: 6/8/2006 Last visit: 11/18/2024 Posts: 17 Rating: (3)	There could be a lot of reasons. This might be a question to address with the OP manufacturer. Have those CPU's been tested? The AS511 protocol has always been closely guarded. They may not have adapted their codetocover all CPU ranges. Ifallelsefails,convert it over and use a Siemens OP.
	Peter Sigma Automation www.sigmaautomation.net sigmaautomation@earthlink.net
Suggestion To thank Quote Answer

1/24/2008 8:57 PM	Rate (0)
GrzegorzG Posts: 63 Rating: (19)	I think that your problem is in CPU memory address organization. CPU928B uses 16bit address while (as I remember) CPU948 has wider (20bit) address space. I've met the same problem trying to use OP with CPU945.
GrzegorzG Posts: 63 Rating: (19)
Suggestion To thank Quote Answer

1/25/2008 12:11 AM	Rate (0)
Schmiermerker Posts: 2 Rating: (0)	Yes, I've been checking some things and that seems to be the problem. The memory adressing of the 948 and the 946/947 is 20-bit compared to the 928b (16-bit). AS511 protocol sends 16-bit addresses, so the protocol must have some sort of work around of this problem which is not taken into account with this driver. I contacted the supplier of the OP (Lauer) and their AS511 driver isn't tested with CPU948 and CPU946/947. They have a special driver for AS511 with CPU945 (also 20-bit adressing, I think), but this one also doesn't work with the 948 or 946/947 (I tried it). I remember from a previous job I've done that there is a difference in the memory addressing between 945 and 948 where the adressing of the 945 is in bytes and the adressing of the 948 is in words. Since the 946/947 is compatible with the 948, I guess the AS511-CPU945 driver won't work either. I'm afraid there is no solution to my problem.
Schmiermerker Posts: 2 Rating: (0)
Suggestion To thank Quote Answer

9/5/2014 9:37 AM	Rate (0)
CS Moderator Moderator Joined: 9/1/2005 Last visit: 12/3/2024 Posts: 4114 Rating: (195)	follow up question published by Ziemensis split to a seperate thread with the subjectwhich protocol the CPU948 use for communication with OP or PG Best regards CS Moderator
	My Forum is the place to personalize your profile, track your topics, and maintain content that interests you. Best regards CS Moderator
Suggestion To thank Quote Answer

|

Share this page:

Share this page on...

Follow us on