User`s manual

www.vtiinstruments.com
EX7000 Series Basic Operation 27
When enabled as an output, each channel also has the ability to generate a 1 µs pulse upon
command. An example application of this pulse is to use the EX7000 to externally trigger another
piece of test equipment. The specific operation of the pulse depends on the static level
programmed for that channel. When a channel is programmed with a static level of high, the pulse
will be low-going. When a channel is programmed with a static level of low, the pulse will be
high-going. Each pulse generation requires a separate command.
The electrical specifications for the digital I/O port are provided in Table 3-1. Particular note
should be given to the V
INPUT
specification of -0.5 V to 5.5 V. Exceeding that value with an
external voltage source, even through a resistance, could permanently damage the EX7000.
Characteristic
Value
V
INPUT
-0.5 V to 5.5 V
V
IH
2 V min
V
IL
0.8 V max
V
OH
(I
OH
= -32 mA)
2 V min
V
OL
(I
OL
= 64 mA)
0.55 V max
TABLE 3-1: DIGITAL I/O PORT ELECTRICAL SPECIFICATIONS
General Purpose I/O
The EX72SF features an additional 32-bit general purpose TTL I/O port. This is in additional to
the internal 72-channel relay drivers and the 8-bit digital I/O described above. The following are
the pin assignments for the rear-mounted 37-pin D-sub connector:
Pin
Signal
Pin
Signal
1
GND
20
PIO-PORT0
2
PIO-PORT1
21
PIO-PORT2
3
PIO-PORT3
22
PIO-PORT4
4
PIO-PORT5
23
PIO-PORT6
5
PIO-PORT7
24
PIO-PORT8
6
PIO-PORT9
25
PIO-PORT10
7
PIO-PORT11
26
PIO-PORT12
8
PIO-PORT13
27
PIO-PORT14
9
PIO-PORT15
28
GND
10
+5 V
29
GND
11
PIO-PORT16
30
PIO-PORT17
12
PIO-PORT18
31
PIO-PORT19
13
PIO-PORT20
32
PIO-PORT21
14
PIO-PORT22
33
PIO-PORT23
15
PIO-PORT24
34
PIO-PORT25
16
PIO-PORT26
35
PIO-PORT27
17
PIO-PORT28
36
PIO-PORT29
18
PIO-PORT30
37
PIO-PORT31
19
GND
A current limited supply of +5 V is provided on pin 10. An internal, resettable fuse is provided to
protect 200 mA against excessive current flow and short circuits.