The 8 channels relay output /photo isolator input board for pocket DIO provides relay output functions and photo isolator input functions. The relay output part provides 8 Single Pole Single Throw (SPST) relays to drive 8 different output channels. Each relay channel can be used to control ON / OFF of external devices, to drive external high power relays, to activate alarms¡K.etc.

The photo isolator input part provides 8 photo couple digital input channels, which allow the input signals to be completely floated and prevent the ground loop.

Features of 8 Channels relay output / 8 channels photo isolator input board:

*Support 8 relay output channels
*Max contact rating for relay : 120V AC/DC 1 AMP.
*Attraction time for relay : 3 ms.
*Fall off time for relay : 2 ms.
*Isolation resistance for relay: 100 ohms.
*Life expectancy for relay: 5 million operation at full load.
*The Normal Open (NO) and Common contacts (COM) of each relay is brought out to the screw connector
*Breakdown voltage: AC/DC 500V minimum.
*Allow the photo input signals to be completely floated and prevent the ground loops.
*Input current : 80mA maximum for each isolated input.
*Input voltage : 15V DC maximum for each isolated input.
*LED indicates when corresponds channel is activated.
*Isolated or non-isolated modes selectable.

Hardware Connections

Hardware Configurations
Before you use the terminal board, you must ensure to have this board plugged into 8255 card.

The LED17 in terminal board shows the power on status. When it lit, there is an applied power on the board, otherwise there is no power.

The jumpers are used to select isolated or non-isolated mode, when open the jumpers it set to isolated mode, otherwise when short the jumpers, the setting is non-isolated mode. JP1 and JP2 correspond to channel 0, JP3 and JP4 correspond to channel 1, etc. When set to isolated mode, the IxL is short to system ground. (where x is the channel number)

Pin Assignment of TB1 (Photo Isolator)

Pin Assignment of T2 (Relay Output)