VXI VT1433B, User Manual, Page: 144 / 203

Dis-allowed Connections
Do NOT connect these pins on VT1432A/33B end of cabling. These signals and
supplies are provided for VXI Technology specified break out boxes and are
unspecified for other usage
Do not use:
15 I2C_EN
17 I2C_SDA
21 I2C_SCL
16 RFI GND/I2C Shield
18 RFI GND/I2C Shield
22 RFI GND/I2C Shield
19 BOB_EN
7 CAL_LOW
20 CAL_HIGH
23 -24 V Power
24 ±24 V GND Return
25 +24 V Power
In general:
q
± DIFF n lines are the differential inputs for each channel. Shielded twisted-pair is
recommended.
q
RFI GND/Drain Shield n are the grounds for the shield on the twisted-pair for each
input channel. Connect at the VT1432A/33B end of the cable only.
q
RFI GND/Cable Shield are the grounds for a shield around the entire cable and the
ground points for making individual channels single-ended.
q
I2C_xxx supply control signals to the active break out boxes. Support is not provided
for any other use. These are not used with the VT3240/1A Voltage and Voltage/ ICP
®
break out boxes.
q
RFI GND/I2C Shield protects the analog input lines.
q
BOB_EN is another break out box control signal. Support is not provided for usage
with anything except certain VXI Technology-specified break out boxes.
q
CAL_HIGH/LOW are signal lines to send calibration signals to the
VXI Technology-specified break out boxes. The signals available on these lines are
not specified and their usage is discouraged.
q
±24V Power and GND supply power to the signal conditioning circuitry in the active
break out boxes and ICP
®
in the active ICP
®
break out box. The power available on
these lines is not specified and their usage is discouraged.
VT1433B User's Guide
Break Out Boxes
8-8