Allen-Bradley ClutchBrake PLC-5 Series - Programming a Variable Speed Top Stop

4–28 Write Ladder Logic
Publication 65566.5.1 - October 1996
The purpose of the variable-speed top stop program is to make the
press stop at the top when commanded, regardless of press speed.
Requirements of this program are the following:
• You must use a resolver as a position monitoring device
• Your program must simulate the action of rotary cam limit switches
• Your program should adjust the TCAM setting only during
downstroke. Shifting the TCAM in any other zone of the press
cycle may trigger a software cam-transition fault.
In the following example program (Figure 4.28), N123:36 holds the
press speed which is buffered once per stroke at 90
o
. The LES and GTR
instructions in the TCAM rung are used for backing the TCAM OFF
position from 340 to 300
o
for increasing press speeds of 10 to 26 SPM.
Figure 4.28
Example
Program for a V ariablespeed T op Stop
| +–SBR––––––––––––––––––––+ B150 |
+––+ SUBROUTINE +–––––––––––––––––––––––––––––––––––( )––|
| | Input Parameter | 0 |
| +––––––––––––––––––––––––+ |
| |
| Resolver Store Press |
| Position Speed Inputs |
| +–GEQ––––––––––––––––––––+ B170 +––––––––––––––––––––––+ |
+––+ GREATER THAN OR EQUAL +–[ONS]–––––––––+ MOVE +––|
| | Source A N80:0 | 10 | Source N123:36 | |
| | | | 128 | |
| | Source B 200 | | Dest N80:1 | |
| +––––––––––––––––––––––––+ | 128 | |
| +––––––––––––––––––––––+ |
| |
| |
| Resolver |
| Position TCam |
| +–LES––––––––––––––––––––+ +–LIM––––––––––––––––––––+ B151 |
+–+–+ LESS THAN +–––+ LIMIT TEST (CIR) +––+––( )––|
| | | Source A N80:1 | | Low Limit 170 | | 0 |
| | | 128 | | | | |
| | | Source B 100 | | Test N80:0 | | |
| | | | | 110 | | |
| | +––––––––––––––––––––––––+ | High Limit 340 | | |
| | +––––––––––––––––––––––––+ | |
| | | |
| | Resolver | |
| | Position | |
| | +–LIM––––––––––––––––––––+ +–LIM––––––––––––––––––––+ | |
| +–+ LIMIT TEST (CIR) +–––+ LIMIT TEST (CIR) +––+ |
| | | Low Limit 101 | | Low Limit 170 | | |
| | | | | | | |
| | | Test N80:1 | | Test N80:0 | | |
| | | 128 | | 110 | | |
| | | High Limit 140 | | High Limit 337 | | |
| | +––––––––––––––––––––––––+ +––––––––––––––––––––––––+ | |
| | | |
Programming a
Variablespeed Top Stop