VTI Instruments Metek EX1202 User Manual page 66

VTI Instruments Corp.
In addition to a single-master/multiple-slaves configuration, the Trigger Bus can be configured in
Wired-OR mode. This mode allows multiple instruments to bring an LXI Trigger Bus channel to a
"1" state. The channel will only go back to "0" when all instruments have released it. This is
useful if multiple instruments in parallel operation must all complete before another instrument
can begin its operations. Each channel is programmable as to whether it is in Wired-OR or Master-
Slave mode.
When an Trigger Bus channel is configured for Wired-OR mode, exactly one instrument on the
bus must provide a bias on the channel. This is what allows the channel to fall deterministically
back to a "0" state when all other devices release it. Each channel is programmable as to whether
it will provide the Wired-OR Bias when it is in Wired-OR mode. The default selections are:

Wired-OR mode is off

Wired-OR Bias mode is off
DMM Front Panel Connectors (Optional)
These connections allow for use of the onboard DMM in measurements. The DMM and its
connections are further discussed in Section 4.
DMM Bus I/O
For EX1200 mainframes with a DMM, it is possible to access the DMM through the DMM bus as
an alternative to the front panel banana jacks (see DMM Input Connections in Section 4 for more
detail on the DMM front panel connector). Alternatively, the bus can be used to route signals to an
external DMM though this connector. To use the onboard DMM, the DMM inputs must be
assigned to the backplane instead of the front panel. Please see Table 3- below for a description of
the bus signals. Note that, when IN and OUT DMM Bus connectors exist on a mainframe, the pin
mapping for each connector is identical.
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Pin
1
2
3
4
5
6
7
8
9
T 3-5: DMM B I/O P
ABLE US
EX1200 Series Basic Mainframe Operation
Function
+SHI
N/C
+HI
N/C
+DAMPS
-SLO
GUARD
-LO
N/C
S
IN IGNALS