VTI Instruments Ametek EX1200A Series, User Manual

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EX1200A Series Basic Mainframe Operation 67
The electrical specifications for the digital I/O port are provided in Table 3-2. 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 EX1200.
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
T
ABLE
3-2: D
IGITAL
I/O P
ORT
E
LECTRICAL
S
PECIFICATIONS
Trigger Bus
The EX1200A provides an compatible trigger bus connector set on the rear panel of the
instrument. Both connectors have the same pin assignments and are wired in parallel. For more
information on the Trigger Bus and creating an appropriate cable, please visit
www.lxistandard.org and refer to LXI Standard Revision 1.2 and LXI Trigger Bus Cable and
Terminator Specifications Rev 1.1 .
Pin Function Pin Function
1 +3.3 V 14 RP_TRIG_P0
2 GND 15 RP_TRIG_N0
3
RP_TRIG_P1
16
RESERVED
4 RP_TRIG_N1 17 RP_TRIG_P2
5 GND 18 RP_TRIG_N2
6
RP_TRIG_P3
19
GND
7
RP_TRIG_N3
20
RP_TRIG_P4
8 GND 21 RP_TRIG_N4
9 RP_TRIG_P5 22 GND
10
RP_TRIG_N5
23
RP_TRIG_P6
11 RESERVED 24 RP_TRIG_N6
12 RP_TRIG_P7 25 RESERVED
13
RP_TRIG_N7
T
ABLE
3-3: T
RIGGER
B
US
C
ONNECTOR
P
IN
A
SSIGNMENT
For proper operation, each trigger bus connector must be populated with either a cable or a
termination. Since the two connectors per unit are in parallel, they are electrically equivalent with
respect to receiving the cable or termination. VTI Instruments P/N: 70-0322-000 provides two
termination assemblies, which is sufficient to connect any number of instruments, since a
termination is only needed at each end. An example of a three-unit trigger bus installation is
shown in Figure 3-1.
1 2 3 4 5 6 7 8 9 10 11 12 13
14 15 16 17 18 19 20 21 22 23 24 25