Allen-Bradley ClutchBrake PLC-5 Series - Page 112

7–6 Set Up or Simulate Rotary Cam Limit Switches
Publication 65566.5.1 - October 1996
We present ladder logic to simulate rotary cam limit switches (Figure 7.5).
Use software bits TCAM (B151/00), BCAM (B151/01), and ACAM
(B151/02) to simulate hardware cams when using resolver or encoder
inputs. (We assume that the resolver module is in slot 0 at address I:000.)
Figure 7.5
Ladder
Logic to Simulate RCLSs When Using Resolver Inputs
| Store Resolver |
| Inputs |
| +–MOV––––––––––––––––– + |
+––––––––––––––––––––––––––––––––+ MOVE +––|
| | Source I:000 | |
| | 0 | |
| | Dest N155:0 | |
| | 0 | |
| +––––––––––––––––––––––+ |
| |
| Takeover |
| Cam |
| +–LIM––––––––––––––––––––+ B151 |
+––+ LIMIT TEST (CIR) +––––––––––––––––––––––( )––––+
| | Low Limit 170 | 00 |
| | | |
| | Test N155:0 | |
| | | |
| | High Limit 350 | |
| +––––––––––––––––––––––––+ |
| Brake |
| Monitor |
| Cam |
| +–LIM––––––––––––––––––––+ B151 |
+––+ LIMIT TEST (CIR) +––––––––––––––––––––––( )––––+
| | Low Limit 10 | 01 |
| | | |
| | Test N155:0 | |
| | | |
| | High Limit 190 | |
| +––––––––––––––––––––––––+ |
| |
| Anti-repeat |
| Cam |
| +–LIM––––––––––––––––––––+ B151 |
+––+ LIMIT TEST (CIR) +––––––––––––––––––––––( )––––+
| | Low Limit 280 | 02 |
| | | |
| | Test N155:0 | |
| | | |
| | High Limit 240 | |
| +––––––––––––––––––––––––+ |
If NOT using anti-backlash couplings and you experience reverse-motion
faults (Faults 033 and 113) due to gear chatter, you may need to modify
your ladder logic to shift cam turn ON and turn OFF positions back about
5
o
instantly at each transition to compensate for gear chatter (Figure 7.6).