Omega DP461-S, Руководство пользователя, Страница: 158 / 175

16
External Control Lines
16-3
16.13 PUSH TO CAL (PIN 14)
See Section 16.6.
16.14 +V EXT (PIN 15)
This is the pin on which to bring in isolated external 5 to 30 V to power the
snubbing diodes of the four setpoint/alarm open-collector transistors.
16.15 SP1 (PIN 16)
The open-collector of the first setpoint transistor
(can carry 150 mA).
16.16 SP2 (PIN 17)
The open-collector of the second setpoint transistor
(can carry 150 mA).
16.17 AL1 (PIN 18)
The open-collector of the third setpoint (first alarm) transistor
(can carry 150 mA).
16.18 AL2 (PIN 19)
The open-collector of the fourth setpoint (second alarm) transistor
(can carry 150 mA).
16.19 RTN EXT (PIN 20)
This is the return to the external ground (P2-20) of the external power for the
setpoint transistors and snubbing diodes brought in on P2-15, 16, 17, 18 and
19. Figure 16-2 shows an example of a circuit using an external relay with
SP1 (Setpoint 1). If a solid state relay is used, delete connection to Pin 15.
Figure 16-2. Connection of External Power for Setpoint Transistors
RELAY
EXTERNAL
DC POWER
P2
16 20
15 1
+
-