Thermo Ramsey - Hoferick Engineering GmbH

Digital Input/Output
D.2. Digital Input/Output Board Configuration
In addition to the programmable digital inputs and outputs on the motherboard,
optional Digital I/O (DIO) expansion boards can be added. Available boards are
DIO input board 16 inputs/4 outputs, output board 16 outputs/14 inputs or 20
inputs/20 outputs by adding both boards.
Both DIO boards provide isolated contact closure inputs and 24-volt current
sinking (default) or current coursing (consult Factory) isolated outputs. The
DIO input board connector J16 is male 25 pin sub-miniature D Connector and
the DIO output board connector J15 is a female connector.
Selectable jumpers OP1 and OP2 located on the lower right hand side of the
DIO boards control internal or external 24 VDC power for the DIO boards. All
inputs and outputs use the same selected power supply.
Appendix Table D-1: DIO Board Jumper Settings (OP1/OP2)
DIO BOARD JUMPER SETTINGS
POWER SOURCE OP1 OP2
INTERNAL “A” “A:
EXTERNAL “B” “B”
The isolated contact closure inputs are activated by completing the circuit from
the input to the negative side of the 24 VDC supply. Approximately 6 mA of
current flows out of each input during contact closure.
The outputs of the DIO boards use 2803 current sinking (default) type IC’s. The
output IC’s are installed in sockets to allow replacing the output IC only rather
than the board if the IC is damaged.
The output IC’s can be replaced with 2981 type IC’s for current sourcing
applications. Wire jumpers W1 through W4 must be relocated for current
sourcing. In most cases, it is recommended the boards be returned to the factory
for converting from current sinking (default) to current sourcing.
Appendix Table D-2: DIO Board Jumper Settings for Current Sourcing
JUMPERS
CURRENT W1 W2 W3 W4
Sinking (default) “Yes” “No” “Yes” “No”
Sourcing “No” “Yes” “No” “Yes”
Thermo Fisher Scientific Multi-Point Calibration D-3
REC 4175 Rev B