if you want to keep your sanity....
I was all excited to learn that the newest version of the DASABCIP driver for wonderware finally supports SLC 505 for ethernet. Until I actually tried to use it. I have around 2800 tags on a current install and was dismayed to discover that 20% of my tags weren't updating. After ALOT of investigation, I discovered that it was all tags that were either I or O data files. B, F, N, T and anything else worked fine, but tags linked to the Input and Output image registers did not. I happen to use alot of these as I have maintenance pages that visually mimic EVERY I/O module, RIO device, etc. for troubleshooting purposes.
Anyway, I dug out the pdf for this driver (who ever reads the manual first, right). There it was... Even though this driver supports SLC, it DOES NOT SUPPORT dot words. In otherwords, you cannot access an address such as I:1.24/10 (a Rack on an RIO Scanner module), or I:7.1 (channel 1 of an RTD module in slot 7). Nooooo....That would be too easy. They basically tried to take a PLC5 protocol and mush it together to support SLC. So, what you have to do is access them according to how many words in the rack.
For example, let's say in the main rack you have Slot 1, a 1746-IA16 module. No problem, the addresses supported are I:1/0 to I:1/16. Let's say the next module is a 1746-NR8 (8 channel RTD). You cannot access I:2.0 through I:2.7. Nope, no sirreee. You HAVE to access them as I:2 through I:9 (as they are the next 8 words). How confusing is that???? Hold on, it gets worse. Now your third module is an OW16 (16pt ouput). That's not O:3/0...Nope, it is O:1/0 to O:1/16 because it is the first OUTPUT on the rack. Now, here comes the final kicker. Suppose you leave some space in between your modules and then later add one. Well guess what? All your WW item names now have to be shifted by one word (or 8 words if you add an analog module).
I shake my head at this ****. The WW docs say copy all your I/O to Integer files to avoid some of these issues. No thanks. Because I actually use the ItemName (via the .Reference) in my displays for troubleshooting purposes. So, I'll bite bullet and buy RSLinx classic.
I know most of you (and me) are on CLX platforms now and won't have this issue as the DASABCIP server is great for CLX. But for those of us poor slobs who have customers that insist on SLC, factor in the cost of Linx and don't rely on the DAS server, at least at its current state.
I was all excited to learn that the newest version of the DASABCIP driver for wonderware finally supports SLC 505 for ethernet. Until I actually tried to use it. I have around 2800 tags on a current install and was dismayed to discover that 20% of my tags weren't updating. After ALOT of investigation, I discovered that it was all tags that were either I or O data files. B, F, N, T and anything else worked fine, but tags linked to the Input and Output image registers did not. I happen to use alot of these as I have maintenance pages that visually mimic EVERY I/O module, RIO device, etc. for troubleshooting purposes.
Anyway, I dug out the pdf for this driver (who ever reads the manual first, right). There it was... Even though this driver supports SLC, it DOES NOT SUPPORT dot words. In otherwords, you cannot access an address such as I:1.24/10 (a Rack on an RIO Scanner module), or I:7.1 (channel 1 of an RTD module in slot 7). Nooooo....That would be too easy. They basically tried to take a PLC5 protocol and mush it together to support SLC. So, what you have to do is access them according to how many words in the rack.
For example, let's say in the main rack you have Slot 1, a 1746-IA16 module. No problem, the addresses supported are I:1/0 to I:1/16. Let's say the next module is a 1746-NR8 (8 channel RTD). You cannot access I:2.0 through I:2.7. Nope, no sirreee. You HAVE to access them as I:2 through I:9 (as they are the next 8 words). How confusing is that???? Hold on, it gets worse. Now your third module is an OW16 (16pt ouput). That's not O:3/0...Nope, it is O:1/0 to O:1/16 because it is the first OUTPUT on the rack. Now, here comes the final kicker. Suppose you leave some space in between your modules and then later add one. Well guess what? All your WW item names now have to be shifted by one word (or 8 words if you add an analog module).
I shake my head at this ****. The WW docs say copy all your I/O to Integer files to avoid some of these issues. No thanks. Because I actually use the ItemName (via the .Reference) in my displays for troubleshooting purposes. So, I'll bite bullet and buy RSLinx classic.
I know most of you (and me) are on CLX platforms now and won't have this issue as the DASABCIP server is great for CLX. But for those of us poor slobs who have customers that insist on SLC, factor in the cost of Linx and don't rely on the DAS server, at least at its current state.