VXi Computer Hardware VX1410A User Manual

Page of 360
Reference
VX1410A & VX1420A IntelliFrame Mainframe Instruction Manual
3–3
Table 3–1: Passive monitor connector pinouts (Cont.)
Pin
Description
Function
24
Gnd
Logic Ground
25
RSV
Request Service signal
5
1
To monitor, only use a probe with greater than 1 M
 impedance.
2
By momentarily grounding this line, the mainframe will toggle from on to off (or vice
versa). The state changes on the falling edge of the signal. Hold the signal low for at
least 500 ms before releasing. Attach only a momentary switch or an open collector
device to drive this line. The line is pulled up to 1 V internally.
3
If you use pins 8 and 21 (+5 VB) to supply +5 V Standby to the backplane, make sure
that the rear panel jumper is in the correct position (refer to Enhanced Monitor Board
Jumpers
 on page B–4).
4
Refer to VMEbus Specification Manual for details on using the ACFAIL* and
SYSRESET* signals.
5
The RSV signal is equivalent to the IEEE 488.1 SRQ signal. The signal is asserted (0)
when an enable event is generated; the signal is unasserted(1) when the event is
cleared by reading the event register. This line is an open collector output. The
signal can be stand-alone or multiple mainframes can be tied together. If you tie
multiple mainframes together, each mainframe must be polled to determine the
source of the service request.