User`s manual

XP8000 Series (PLCBus
TM
) Z-World 530-757-3737 15
Each input channel can be pulled high to an excitation voltage
(which can be external or V+) or pulled to ground, depending
on the setting of jumpers J2, J3, J4 and J5.
Universal Inputs As Digital Inputs
When the negative side is connected to VL, the inputs function
as digital inputs: the channel read “1” when the input voltage is
more positive than its threshold voltage and “0” otherwise. The
threshold voltage is given by this expression:
V
THRESHOLD
= CV+ ×
R5
R4 + R5
Universal Inputs as Digital Inputs with Two Thresholds
The input channels can be used as digital channels with two (or
more) thresholds specified in software when the negative side
of the comparator is connected to an external analog voltage
source. Presumably, the external source is a DAC operated by
the system’s controller. (Z-World’s PK2100 has such a DAC out-
put.) When an input voltage is higher than its upper threshold,
the channel becomes “1” and when it goes below its lower
threshold, the channel becomes “0.” The digital result does not
change (in software) when the input is between thresholds.
This feature offers stability for some kinds of inputs.
Universal Inputs as Analog Inputs
The input channels can be used as analog channels when the
negative side of the comparator is connected to an external
DAC. Because the comparator threshold can be varied, it is pos-
sible to take an analog reading by successive approximation.
The accuracy of such a reading depends, in part, on the accu-
racy of the DAC.
The High-Current Output(s)
Six high-current outputs drive external loads (/LO–/L5) such as
relays or small actuators.
+VI
SUB
+V
K SUB
2003
driver
U10
D0–D3
/L0–/L5
20K
6
259
Protection
6
J1
10
12
14
The voltage supplied to the outputs can be +V from the PLCBus
or an external voltage (+VI) from the header H3. If you supply
an external voltage, connect SUB (also on H3) to external
ground. Diodes internal to the 2003 protect the driving transis-
tors against spikes.
The driver chips dissipate up to 1.25W at 60°C. With six chan-
nels on at the same time, the maximum current is ~160 mA per
channel. The maximum current per channel is 500 mA.
How to use a Universal Input/Output Board
The general method for using a UIO board is this:
1 Initially, send a reset command to all boards on the PLCBus.
2 Get the board’s attention by placing its address on the
PLCBus.
3 Read the inputs on the board, or perform output.
Addressing the Board
Each UIO board can have one of 16 PALs. Jumper J1 (pins 1-2)
be set two ways. Thus, there can be 32 UIO boards on a single
PLCBus. Each board’s address has this format:
0000 010p pppx
pppp is determined by the PAL
x = 1 when J1 pins 1-2 are not connected.
UIO board addresses, therefore, range from 0x040 to 0x05F.
Software give the UIO logical addresses. Each UIO channel has
an address, according to the formula:
address = board << 4 + channel.
Operating the Board
The UIO board has 16 universal inputs and six high-current out-
puts. To access an input channel or an output channel, write to
the board’s latch using BUSWR:
D3 D2 D1 D0 Meaning
000x Set or clear /L0 for high-current outputs 0–5
001x Set or clear /L1
010
x Set or clear /L2
011
x Set or clear /L3
100
x Set or clear /L4
101
x Set or clear /L5
110
xUnused
111x Set up a read. When D0=0, select even input chan-
nels. When D0=1, select odd input channels
Setting an output driver is straightforward.
Reading one of the input channels (in digital mode) is slightly
more complicated. There are two different read cycles.
BUSRD1 corresponds to input channels 0–7. BUSRD2 corre-
sponds to channels 8–15. You must also set up for a read: writ-
ing 0xE to the latch selects even input channels. Writing 0xF
selects odd input channels. Thus, the BUSRD1 and BUSRD2
cycles read 4 channels at a time, one bit per channel, in D3–D0.
The various bus cycles have specific meaning when using a
UIO board:
BUSWR Write data.
BUSRD0 Determine the presence of a UIO board. Bit 0, when 0,
indicates the presence of a board.
BUSRD1 Read input channels [0, 2, 4, 6] or [1, 3, 5, 7].
BUSRD2 Read input channels [8, 10, 12, 14] or [9, 11, 13, 15].
BUSRESET Resets all expansion cards on the PLCBus.
Higher level functions available in Dynamic C libraries take
care of the details of much of this.
Specifications
Board Size 2.835 × 3.525 × 0.75
Operating Temp –40°C to +70°C
Humidity 5% to 95% non-condensing
Power
24VDC, 45 mA
Provides 16 “universal” channels. 6 high-current output
channels, sinking continuously
150 mA at 48V
at 50°C (all on) or 500 mA continuously at 48V
at 25°C (one channel at a time).