Rockwell Automation 1747-L40 SLC 500 Fixed Hardware Style - Manual (Page 60)

Chapter 4
Installing Your Hardware Components
4–5
Removing Your Memory Module
To remove a memory module use the following procedure:
1. Remove the power from the fixed I/O unit.
2. Remove the processor compartment cover.
3. Grasp the carrier tabs with the thumb and index fingers, then gently but
firmly lift upwards on either end of the memory module carrier.
4. When the end is partially raised, begin lifting the other end in the same
manner. Repeat this until the memory module has been completely
removed from the socket.
5. Replace processor cover.
The fixed I/O units that have 24 VDC input circuits are also equipped with a
high–speed counter. The counter is capable of counting at a rate of up to 8 kHz.
You have the option of using input 0 as a normal input or as a high–speed
counter. To accommodate this dual function the input is equipped with a
jumper selectable filter. You must cut the jumper for high–speed counter
use. A shielded cable is recommended to reduce noise to the input.
High-Speed Counter Operation
For high–speed counter operation do the following:
1. Turn off power to the fixed controller.
!
ATTENTION: When power is applied to the controller
hazardous electrical potentials exist under the front cover. See
page 2–8 for more information.
2. Remove the SLC 500 cover.
3. Locate and cut jumper wire J2. The jumper is either beneath or to the
right of the battery connector, as shown below. Do not remove
completely but make certain that the ends of the cut jumper wire are not
touching each other.
Using the High-Speed Counter