ALLEN BRADLEY 1747-L551 PLC Processor

Starting Up Your Control System
8–11
7. Observe Control Motion
Now that program execution has been verified, checkout of control
motion can begin. All persons involved with the programming,
installation, layout design, machine or process design and
maintenance should be involved in making decisions for determining
the best and safest way to test the total system.
The following procedures are general in nature. Individual
conditions may warrant their modification. The basic approach is to
initiate testing with the least amount of machine motion. Only some
outputs are allowed to generate machine motion. Then additional
machine motion can be gradually added, thereby allowing any
problems to be detected more easily under controlled conditions.
The following procedure provides the steps for testing machine
motion using one output at a time.
!
ATTENTION: During all phases of checkout, station
a person ready to operate an emergency-stop switch if
necessary. The emergency-stop switch will
de-energize the master control relay and remove power
from the machine. This circuit must be hardwired
only, it must not be programmed.
Use the following procedures:
1. Identify the first output device to be tested and reconnect its
wiring.
!
ATTENTION: Contact with AC line potential may
cause injury to personnel. When reconnecting wiring,
make sure that the AC power disconnect switch is
opened.
2. Place the controller in the Run mode and observe the behavior of
the output device. To do this, simulate the input conditions
necessary to energize the output in the program. If it is not
practical to manually activate an input device, use the force
function to simulate the proper input condition.
!
ATTENTION: Never reach into a machine to actuate
a device, unexpected machine operation could occur.
3. Repeat steps 1 and 2, testing each output device, one at a time.
Publication 1747-6.2