Rice Lake 120 Plus Digital Weight Indicator - Manual (Page 15)

Installation 11
2.4.2 Setpoints Output
Output drivers for the 120 Plus are isolated open emitter transistor drives that are capable of driving up to
a total of 800mA. This configuration allows for the direct connection of the 120 Plus outputs to most types of
PLC.
The voltage applied to the COM terminal appears on the output lines (i.e. OUT1 and OUT2) when the outputs are
active (e.g. To connect to a PLC connect +24V to the common terminal). The outputs can then be connected
directly to PLC inputs so when the outputs are active the PLC will see a 24V signal.
To drive external loads (e.g. relays), connect the relay coil positive supply to the output common and the output
line directly to one side of the relay coil. Connect the other end of the relay coil to the negative supply. It is
recommended that fly-back diodes or transient suppressors be fitted across relay coils to limit switching noise.
Figure 2-10. Connect Setpoints Outputs to Drive Relay
Figure 2-11. Connect Setpoints Outputs to Drive PLC
HDB15
4
10
5
Power +12~24V DC
(Max. 50V)
Negative Supply
OUT1
OUT2
120 Plus
HDB15
4
10
5
Power +12~24V DC
(Max. 50V)
OUT1
OUT2
Input 1
Input 2
COM
PLC
Negative Supply
120 Plus