Trident Model PD765 Universal Input Meter Instruction Manual
20
Serial Communication
Serial communication connection is made to an RJ11 connector labeled
SERIAL on Figure 2. Use PDA7232 for RS-232 interfacing.
Use PDA7422 for RS-485 interfacing.
Use PDA7420 for meter-to-meter interfacing for cloning purposes (
i.e.
copying programmed settings from one meter to other meters).
Relays and 24 V Output Connections
Relay connections are made to a six-terminal connector labeled
RELAY1, RELAY2 on Figure 2. The COM (common) terminals of the re-
lays should not be confused with the COM (common) terminal of the
SIGNAL connector. The 24 VDC output is available at the connector la-
beled 24V OUT, next to the relays connector.
Figure 12. Relay & 24 V Output Connections
Switching Inductive Loads
The use of suppressors (snubbers) is strongly recommended when switching in-
ductive loads to prevent disrupting the microprocessor’s operation. The suppres-
sors also prolong the life of the relay contacts. Suppression can be obtained with
resistor-capacitor (RC) networks assembled by the user or purchased as com-
plete assemblies. Refer to the following circuits for RC network assembly and in-
stallation:
Figure 13. AC and DC Loads Protection
C
R
C
R
www.
GlobalTestSupply
.com
Find Quality Products Online at: