[MI 019-100] Universal Instruction Manual I/A Series Mass Flow ...

2. Installation MI 019-100 – December 2003
A wiring diagram for a Contact Output is shown in Figure 13.
POSITIVE POWER INPUT
TERMINAL (5)
+ –
24 V dc
CONTACT OUTPUT
TERMINAL (4.2)
+
LOAD*
–
*For example, lamp, relay, coil
Figure 13. Contact Output
The voltage requirement for contact output is 24 V dc ±10%. The load requirement is governed
by producing a maximum current of 100 mA.
Pulse Output
A wiring diagram for a Pulse Output is shown in Figure 14.
POSITIVE POWER INPUT
TERMINAL (5)
+ –
24 V dc
PULSE OUTPUT
TERMINAL (4.1 OR 4.2)
+ –
RECEIVER*
*For example, Model 75 Totalizer
300 Ω
Figure 14. Pulse Output
The maximum pulse current is 80 mA. This requires a minimum 300 Ω pulse load resistor. In
connecting your pulse loop, always place the pulse load resistor at the receiver.
Higher pulse output frequencies require a minimum load.
Sometimes a resistor divider is required because of the bias current of the receiver input. Refer to
Figure 15. In such cases, the bias current times R2 must be less than the maximum low input
threshold of the receiver.
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