User`s manual

XP8500
34 s Software Reference
Expansion Board Addresses
Up to 16 XP8500s may be addressed individually over a single PLCBus.
Each XP8500 has a 12-bit address. The address is determined by the
encoding of PAL chip U9 on the board and by the jumper connections on
headers J4 and J5.
Four different PALs are available and the jumpers can be set four different
ways, giving 16 unique addresses in the form
0000 1100 pqxy
where the PAL determines pq while and the jumper connections on headers
J5 and J4 determine x and y, respectively. x and y are zero when their
corresponding jumpers are installed on the headers, and are one when the
jumpers are removed.
The address can be placed on the bus using 4-bit addressing. The func-
tions set12adr, read12data, and write12data (in DRIVERS.LIB) use
12-bit bus addresses.
When using these, and certain other functions, swap the first and third
nibbles of the address before passing the address to the function. For
example, if the address is 0x125, pass 0x521. The function
eioPlcADC4Addr in EZIOPBDV.LIB is available to do this swap.
 unsigned
_
eioPlcADC4Addr(char BrdAddr)
Swaps bit pattern from 0000 0000 pqxy to pqxy 1100 0000.
PARAMETERS: BrdAddr is the logical address (4*PAL# +
Jumper
_
number
) with a bit pattern of 0000 pqxy, where pq is
determined by the PAL, and xy is determined by the jumper setting.