WOODWARD 9905-971 Linknet 16 Channel discrete Input Module
Description:
9905-971 is a Linknet 16 Channel discrete Input module manufactured by Woodward. It is an essential component in the network. 9905-971 offers sixteen discrete input channels designed for field switches or relay contacts. Each channel inputs repy on a +24 Vdc power supply. A filtered and fused internal power source is provided or an external +24 Vdc source referenced to the 24 V Common of the module may be used to sense the state of the contact or switch. 

Key Features:
▪  16 discrete input channels.
▪  Requires +24 Vdc power.
▪  Supports DIN‑rail mounting and hot‑swappable replacement of faulty nodes without disrupting the network.
▪  Includes address setting via rotary switches to match the network configuration defined in the application program.
▪  Features optoisolated input circuits with status LEDs to indicate when a contact is closed.
▪  Offers high isolation ratings: 277 Vac between network and I/O channels, 500 Vdc between power supply and I/O channels.

Installation:
1. Mount the module on a DIN rail and connect to 24 Vdc power and LINKnet network.
2. Wire inputs using internal +24 V or external +24 Vdc source.
3. Set rotary address switches to match the application program.
4. For hot replacement: keep network connected, install same-address module, then reset via software.
5. Use field wiring up to 14 AWG with proper shielding and grounding.
6. Check communication and clear faults in the application program.

Q&A:
1. What is the maximum current rating of each input channel?
The maximum current rating for each discrete input channel is 13.1 mA per channel (at 24 Vdc, ON state).
2. Can the 9905-971 be used in the hazardous locations?
Yes, 9905-971 approved for Class I, Division 2, Groups A, B, C, D (North American hazardous locations), as well as suitable for non‑hazardous locations.