Help with Limit Logic

[mr_electrician 9]

Hello gentlemen, I am working on a project that is frustrating me. I am trying to create a program that will test transmitters with using air pressure. I have the first steps down but I am stuck at the testing stage. I need 5 stages of testing with 3 sec. intervals in between. My good transmitter will read 400, 800, 1200, 1600, and 2000 with a tolerance of + or - 4. I figure if I can get the first one the other 4 stages will be easy, but being the rookie I am, I have to swallow my pride and ask for your great expertise. This is a lab assignment so all I am looking for is a push in the right direction and if I the logic I have allready is a good start. See the attachment for what is done allready. Also I need to have a fault bit for every stage that fails. These will be reset at the end of the cycle by the operator. I will use the stop button for that. Edited 24 Apr 2007 by mr_electrician

[Gerry 13]

Problem 1: The TT and DN bits of a timer will never be on at the same time, so B3:0/1 will never be set. Problem 2: Any even-value reading in N7:0 will cause N22:2/0 to set when timer T4:1 times out.