Figure 6-4. Multiple SDM-SIO2Rs with separate buses
Before mounting, select and set the SDM address. The SDM address is set with a screwdriver.
(p. 13) 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.
NOTE:
If the address switch is changed, the SDM-SIO2R must be power cycled for the new address
to take effect.
SDM-SIO2R Serial Input/Output Module with Switched Sensor Power
12
