20
turns OFF). Proper operation for power interruptions will not be possible if
NC contacts are used in conjunction with counter, shift, or keeping (latching)
instructions.
2-3-3
Precautions
Unit Sticker
A sticker is provided on the upper face of the CPU to prevent foreign objects,
such as wire clippings, from entering the CPU. Leave this protective sticker
on until the CPU is ready for operation. The sticker must be removed before
operation to enable proper cooling.
Contact Outputs
High inductance on for contact outputs will reduce relay life. Keep inductance
low and use an arc suppressor (such as a diode for DC loads). This is partic-
ular important with inductive DC loads.
Vibration
Relay operation may be adversely affected if the relay is located near contac-
tors, valves, motors, or other devices that produce vibration.
Protective Circuits
We recommend the use of arc suppressors to increase contact life and allevi-
ate the affects of noise. Arc suppressors, however, will delay release time
somewhat and, if used incorrectly, they can inhibit proper operation. The
most common arc suppressors for AC are capacitor-resistor circuits and va-
ristor circuits; for DC: capacitor-resistor circuits, diode circuits, and varistor
circuit. Do not use a capacitor without a resistor as the charging current flow
to the capacitor when current is turned ON can cause the contacts to fuse.
2-4
Programming Console
Open the connector cover of the PC, align the notch on the connector, and
press the connector into place.
Connection to a CPU
Connecting Cable
SP10-CN
__
1
PC
SP
__
SP10-PRO01-V1
Programming Console
Section 2-4