INM 5500 Rev 10
61
8 .2 Digital Output (DO) modules
Apply tests per channel.
8 .2 .1 Loop powered: - MTL5521(-T), MTL5522 & MTL5525
Figure 8 .2: Loop powered DO test circuit
1. Connect a voltmeter between the + & – output terminals of the module, observing polarity.
2. Apply 24V between the supply terminals (Vs+, Vs–)
3. The voltmeter should indicate a value between 21.4 and 24 volts
4. Switch off the power to the module
5. Connect an ammeter between the + & – output terminals of the module, observing polarity
6. Apply 24V between the supply terminals (Vs+, Vs–)
7. The ammeter should indicate no more than 70mA for the MTL5522 and no greater than
48mA for any of the other modules
8. Switch off the power to the module
8 .2 .2
Powered: - MTL5523, MTL5523V, MTL5523VL & MTL5524
Figure 8 .3: Powered DO test circuit
1. Connect a voltmeter between the + & – output terminals of the module, observing polarity
2. Apply 24V between the supply terminals Vs+, Vs–
3. The voltmeter should now include no more than 4V
4. Close the Control switch or, for the MTL5523V or MTL5523VL, apply the 24V source
5. The voltmeter should now indicate a value between 21.4 and 24 volts
6. Switch off the power to the module
7. Connect an ammeter between the + & – output terminals of the module, observing polarity
8. Close the Control switch or, for the MTL5523V or MTL5523VL, apply the 24V source
9. The ammeter should indicate no more than 48mA
10. Switch off the power to the module
8 .2 .3 Relay: - MTL5526
Figure 8 .4: DO test circuit for relay type
1. Set in 2-channel mode (SW1 - SW4 respectively to Off, On, On, On)
2. Confirm continuity between NC and Common
3. Apply 24V between the supply terminals Vs+, Vs–
4. Close the Control switch
5. Confirm continuity between NO and Common
6. Switch off the power to the module
+
–
Vs+
Vs–
i/p
o/p
V
A
+
–
Control
i/p
o/p
V
A
+
–
24V
+
–
MTL5523V/VL
Control
i/p
o/p
+
–
Common
NC
NO
