I inherited a TI505 control system when my employer bought out another company. Now I'm trying to learn about the system so I can maintain and modify it. I've managed to learn a lot about it from the manuals alone, but I've hit a snag understanding the "Scale" command in a SF program. The TISoft manual simply says "Converts binary inputs into engineering units." One SF program in the PLC converts a 4-20ma signal to 1/2 feet using:
SCALE BIN IN: WX14 SCALED RESULT: V21
LOW LIMIT: 0.0 HIGH LIMIT: 100
20% OFFSET: YES BIPOLAR: NO
I understand what this does, takes the input reading from WX14 (from an 8 channel analog i/o board) and gives me the 1/2 feet in V21, but how does it know how to convert the current reading to the correct 1/2 feet?
The ultimate problem I'm trying to solve here is this reading is the fluid level in a storage tank, the previous company was satisfied to have the reading to the nearest 1/2 foot, but we want to see it to the nearest inch.
If anyone can shed any light on this for me I'd really appreciate it.
Dan
SCALE BIN IN: WX14 SCALED RESULT: V21
LOW LIMIT: 0.0 HIGH LIMIT: 100
20% OFFSET: YES BIPOLAR: NO
I understand what this does, takes the input reading from WX14 (from an 8 channel analog i/o board) and gives me the 1/2 feet in V21, but how does it know how to convert the current reading to the correct 1/2 feet?
The ultimate problem I'm trying to solve here is this reading is the fluid level in a storage tank, the previous company was satisfied to have the reading to the nearest 1/2 foot, but we want to see it to the nearest inch.
If anyone can shed any light on this for me I'd really appreciate it.
Dan