How to Calculate Tags in 800xA?
I am wondering if you could help me to calculate Tags for lets say a system with 1200 DI, 500 DO, 600 AI, 200 AO, and 4000 serial IO.
I know that 800xA is dealing with an objects, and in the wizard it is described how to calculate the Tags taking into a consideration AI, DI and Pulse, but they did not mentione anything about soft IO (Serial IO), do I need to consider them or not?
Thank you in advance for your help.
Voted best answer
If the system is in the planning stage, then there is no firm answer to this question.
You can estimate the required number of tags by looking at what your IO is used for. For example, a PID controller uses 1 AI, 1AO and 1 faceplate - so that is one tag. A motor may use 2 DI, 1 DO and one faceplate so that is also only 1 Tag. On/Off valves might have position feedback but typically do not. Sometimes customers expect to see faceplates for every IO point as well as the object and this can increase the number of tags required.
Typically, data transfred over a serial link is not directly displayed on an HMI with individual faceplates for each point, so does not require very many tags.
Obviously, you need to know something about the application to be able to make this kind of decision. Sometimes it is better to look at how many motors, valves, transmitters etc the plant has.
Also, remember that a Tag is any object with a faceplate, so if you want to reduce the number of tags you can remove the faceplate from an object ( Eg in AC450, turning off faceplate inheritance for DAT elements can save hundreds or thousands of tags)
Finally, allow enough spares - say 20 to 40% depending on the assumptions you made when estimating the types of objects you will use.
TAGS can be calculated as:
# of objects with at least one faceplate
# of objects with at least one faceplate found in Object Type Structure
When using 800xA for Advant Master, all four MB300 DAT object types are excluded.
When using 800xA SafeGuard (for Advant Master), each SafeGuard node is counted as one third (1/3) since each SafeGuard controller "comes in threes", SideA + SideB + Virtual.
AFAIK: the afwsysinfo.exe tool's tag count DOES NOT exclude MB300 DAT or SafeGuard objects correct.