Last updated: April 22, 2003

Description:

This 1-wire card uses the DS2450 IC in the 0-5.1V A-D input mode to read the state of four digital status inputs. Each channel has a 10K pullup resistor to +5V. It is expected that you connect a dry contact between Common and the desired input channel.  It can also be connected to the RELAY4B. This board accepts four optically isolated status input modules. These can be any combination of an IAC5 (senses the presence of 90 to 140VAC) or an IDC5 (senses the presence of 3 to 32VDC).

Card Type: 1

Type	Description
1	Selects Input Range 0-5.10V

Connector CN2 Pinout:

Pin Numbers	Description
1	Common
2	Status channel 4
3	Status channel 3
4	Status channel 2
5	Status channel 1
6	+5V Power Output

OWconfig:

The "Type" must be 1 as described above. The "Mode" must always be "Separate power".

Modbus Register Information:

This device has four consecutive Modbus input registers on the ICONIO board, one for each status channel. Each Modbus register value will be around 1000 when the contact is open and around 0 when the contact is closed. Use the following two ICON expressions to convert from Modbus register value (R) to a 1 or a 0 Status value as follows:

Modbus Range	Conversion
0-1023	Status=R/1023 Status=bool(Status)

Specifications:

Parameter	Specification
Temperature	-40 to +85C (-40 to +185F)
Input Impedance	10K ohm
Power	2.5 mA with all contacts closed.

Schematic and Parts List:
 

Reference	Part Number
CN1	Digikey 281-1451-ND
CN2	Digikey 281-1452-ND
D1	Dallas Semi DS9503P
D2-D6	Digikey SA5V0ADICT-ND
U1	Dallas Semi DS2450S