worldofwires

kaiser_will, Yes thanks, I've been through the manuals. I now have a fairly good understanding of the workings of the block transfers but there was just one issue which didn't seem to be explained. That is, how do you know which M buffer address to use? I've configured mine now through a (very) lengthy process of trial and error. When I got one working, I added another IE8 to see if I could and I did... eventually. :) The two BTRs (9 words) use the addresses M1.6.300 and M1.6.200 respectively whilst the corresponding BTW addresses are M0.6.200 and M0.6.100 respectively. That is: IE8 in slot 2 of Flex rack: BTR=M1.6.300 & BTW=M0.6.200 IE8 in slot 3 of Flex rack: BTR=M1.6.200 & BTW=M0.6.100 The examples in SLC instruction set show the same slot and address for both the M buffers and that was all I had to go on really. If there is a method to determine these addresses, I'd be very interested in learning it. For now, my analog modules are working and I'm sick of the sight of PDF files!

Update: I've got it working, it was to do with the M buffer. The SLC instruction help suggested M1.1.100 but it's now working when I tried M1.1.200. I don't know why and that bothers me but its working now and that pleases me. I'm using M0.1.100 not 200 for the BTW though, this doesn't make sense to me but its working. The IE8 is the only analogue module in the system, what else could be using M1.1.100? If anyone has an explanation for this, I'd be grateful. John

I should add, when I say 'old 503' its really a 16k, OS302 Series C. In case it matters. :) EDIT: Whilst looking at this code, can anyone tell me why the refresh rate seems so slow? If I remove the two switches from the BTR rung, it performs much quicker. What's the danger in leaving it always on? And finally, if the Data File sent to the IE8 is only one word, how would you set the Safe State values? Or is that not possible?

Hi all, This is my first post so I hope I cover everything and appreciate any responses. I've worked on AB systems for years but until now, never tried to commission any. I'm just assembling a test rig for flex modules using an old 503 in a 7 slot rack with a 1747-SN scanner. So, I've got an ASB (rev E) with 2 OB16s, an IB16 and an IE8 (Ser B). Reading the manuals for the SN, ASB and IE8 I've got everything but the analogue working. I'm using the PLC 5 ladder suggestions from the manual for the BTR and BTW but something doesn't seem to be right. Channel 0 seems to be working as 4-20mA (as I want) but the other 7 do nothing. I think the problem is the 'Data File' from the BTW because when I sent two words (both -256), all eight channels seem to function. I could leave it like that but I don't have faith that they're correctly configured as I clearly don't understand how it works. The manual reads as if the data sent to configure the module is all on one word, and the example ladder seems to to concur. I assume I'm being stupid but can anyone point out how and where please? I greatly appreciate any help. John