thebuj
Lifetime Supporting Member
Hey guys, I'm going to be replacing at PLC5 cpu with a 1771-ASB and control the racks using an L71 cpu. I got the discrete IO all converted and my control logix program is pretty much done. I'm having problems understanding the analog cards though.
I have one analog out card and one in. The analog out (5/3/0) controls an air pressure valve and the analog in (5/3/1) reads an ultrasonic sensor. The data from the sensor is used to calculate the air pressure to output on the analog card.
I've hit a wall with the analog input module. It has both a read and an write transfer block and I don't have enough experience with configuring PLC5's and I don't understand whats going on.
In my opinion the comments on rung 24 should be really for rung 23 and the comments for rung 25 should be for rung 24.
That leaves me with rung 25 which I don't understand what and why they are writing to an input module.
As you can see N24:101 is nowhere else in the program and N24:131 is also nowhere else in the program. Since both lengths are 0, am I right to assume that only the data file indicated in the control block get written/read?
Anyone know whats going on?
I have one analog out card and one in. The analog out (5/3/0) controls an air pressure valve and the analog in (5/3/1) reads an ultrasonic sensor. The data from the sensor is used to calculate the air pressure to output on the analog card.
I've hit a wall with the analog input module. It has both a read and an write transfer block and I don't have enough experience with configuring PLC5's and I don't understand whats going on.
In my opinion the comments on rung 24 should be really for rung 23 and the comments for rung 25 should be for rung 24.
That leaves me with rung 25 which I don't understand what and why they are writing to an input module.
As you can see N24:101 is nowhere else in the program and N24:131 is also nowhere else in the program. Since both lengths are 0, am I right to assume that only the data file indicated in the control block get written/read?
Anyone know whats going on?