27
Address Selection
The module’s address can be set to any address that is a multiple of 4, such as
address 0, 4, 8, 12, 16, … , 252. This address is known as the base address, with the
module occupying this address plus the next three addresses. Thus if the base
address is 0, then the module occupies the address range 0 to 3.
The address is set with the 6 way DIP switch SW1.
The six address switches, 1 to 6, represent addresses 128, 64, 32, 16, 8 and 4
respectively. The base address is the sum of all the switches in the Off position. For a
piano style DIP switch, as illustrated below, Up is Off and Down is On.
In the illustration below the switches are:
Up
Down
Down
Down
Up
Down
This represents the address:
128 +
0
+
0
+
0
+
8
+
0
=
128 + 8
=
136
(or 0x88 in hexadecimal).
In order to provide some certainty for software it is strongly recommended you set
the base address of your first PIO module to 0x68. If you have a second PIO module
the recommended base address is 0x6C. If everybody follows this recommendation
then software written for the PIO module will know where to find the hardware.
