Z-World XP8600, User Manual

Page: 28 / 99

XP8600 28 s Software Reference
Expansion Board Addresses
XP8600
Up to 64 XP8600s may be addressed individually over a single PLCBus.
Each XP8600 board has a 12-bit address. Once the board has latched its
address, the board may be accessed repeatedly without having to send its
address again.
The 12-bit address of a particular XP8600 is determined by the encoding
of PAL chip U7 on the board and by jumper block J3. Eight different
PALs are available, and J3 may be set eight different ways, giving 64
unique addresses in the form
000z 001y pppx
where
x = 1 when J3 pins 1–2 are not connected
y = 1 when J3 pins 3–4 are not connected
z = 1 when J3 pins 5–6 are not connected
and the PAL determines ppp.
The 12-bit address can be placed on the bus using 4-bit addressing. The
functions
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 physical address before passing the address to the function.
For example, if the address is
0x125
, pass
0x521
.
Logical Addresses
PLCBus expansion boards have “logical addresses.” D/A-specific
software defines 64 integer board addresses, 0–63. The formula mapping
physical address to logical address is
logical address = ppp × 8 + zyx
where ppp (PAL encoding) and x, y and z (jumper bits) are defined above.
For example, an XP8600 has PAL FPO4850 (ppp = 101) and J3 pins 3–4
connected (xyz = 101). Its physical address is
000z 001y pppx = 0001 0010 1011 =
0x12B
.
The XP8600’s logical address is
101
B
× 8 + 101
B
= 45 =
0x2D
.
Certain library functions expect a logical D/A address.
LED
The XP8600 has an LED, D1, which is illuminated whenever the board is
selected.