User`s manual
XP8300/XP8400/SE1100 PLCBus s 63
Device Allocation
4-Bit Devices
Digital output devices, such as relay drivers, should be addressed with
three 4-bit addresses followed by a 4-bit data write to the control register.
The control registers are configured as follows:
bit 3 bit 2 bit 1 bit 0
A2 A1 A0 D
The three address lines determine which output bit is written. The output
is set as either 1 or 0, according to D. If the device exists on the bus,
reading the register drives bit 0 low. Otherwise bit 0 is a 1.
For digital input, each register (BUSRD0) returns four bits. The read
register, BUSRD1, drives bit 0 low if the device exists on the bus.
Table A-4 provides the address allocations for the registers of 4-bit
devices.
8-Bit Devices
Z-Worlds XP8700 and XP8800 expansion boards use 8-bit addressing.
Refer to the XP8700 and XP8800 manual.
Table A-4. Allocation of Registers
A1
A2 A3 Meaning
000j 000j xxxj
digital output registers, 64 registers
64 × 8 = 512 1-bit registers
000j 001j xxxj analog output modules, 64 registers
000j 01xj xxxj
digital input registers, 128 registers
128 × 4 = 512 input bits
000j 10xj xxxj analog input modules, 128 registers
000j 11xj xxxj 128 spare registers (customer)
001j xxxj xxxj 512 spare registers (Z-World)
j controlled by board jumper
x controlled by PAL