LI5X Process & Temperature Meter Instruction Manual
19
SIGNAL CONNECTOR
2
1
3
5
4
RTD TC
1 2 3 4 5 6
COM
mA+
V+
T+
EXC
Switch
Position
RTD
Sensor
NC
Figure 10. Four-Wire RTD Input Connections
The four-wire RTD connection is similar to the three-wire. One of the
leads of a four-wire RTD is not connected, and may be clipped off.
The three-wire connection provides sufficient lead wire compensation to
provide accurate readings even with long leads.
Serial Communication
Serial communication connection is made to an RJ11 connector labeled
SERIAL on
Figure 2
. Use LI97-1001-232 for RS-232 interfacing.
Use a standard modular cable 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
relays should not be confused with the COM (common) terminal of the
SIGNAL connector. The 24 VDC output is available at the connector
labeled 24V OUT, next to the relays connector.
24V OUT
P+ P-
COM NO
NO
NC
NC COM
RELAY2
RELAY1
4
3
6
5
2
1
2
1
Figure 11. Relay & 24 V Output Connections
Spec Tech Industrial Electric
www.spectechind.com
888-773-2832
Spec Tech Industrial Electric
www.spectechind.com
888-773-2832