Mounting

The SDM‑SIO2R is designed to be installed in a dry, non-condensing environment. The SDM‑SIO2R is normally mounted on a DIN rail mounting bracket (as shown in DIN rail mounting) that is then attached to the backplate of a Campbell Scientific enclosure.

A SDM‑SIO2R can be removed from the DIN rail by using a screwdriver to pry on the din rail release bar. See DIN rail release bar.

All SDM‑SIO2Rs that are connected on the DIN rail will share a common bus.

Keep SDM‑SIO2Rs apart to maintain separate buses.

Before mounting, select and set the SDM address. The SDM address is set with a screwdriver. SDM address settings lists the possible SDM addresses and their relationships to the COMPort parameter in the SerialOpen() instruction.

There can be up to 8 SDM‑SIO2Rs on a single SDM bus. Each SDM‑SIO2R will need to be set to a unique address before they are powered. The SDM‑SIO2R has a single address switch. This sets the address of the first serial port of the module (sensor 1). The SDM address of the second serial port will follow sequentially from the port 1 address. For example, if the address switch is set to 4, sensor 1 has SDM address 4 and sensor 2 has SDM address 5. Since each SDM‑SIO2R on the bus takes up two SDM addresses, their address switches must be set with at least one address in between. If an address switch is set to “E” (SDM 14), only the first port of the SDM‑SIO2R is enabled. If any other equipment is present on the bus, whether an SDM‑SIO2R or other SDM device, the user will have to ensure their addresses are unique.

SDM address settings
Rotary switch position	SDM address	SerialOpen() instruction COMPort number
0	0	32
1	1	33
2	2	34
3	3	35
4	4	36
5	5	37
6	6	38
7	7	39
8	8	40
9	9	41
10	10	42
11	11	43
12	12	44
13	13	45
14	14	46
151	151	471
1 Address F is not available as it is the broadcast address. Setting this address will result in the SDM‑SIO2R having an address of 0 rather than F.