Adding Components To The Terminal Module - VXI VT1422A User Manual

Adding Components to the Terminal Module

54 Field Wiring
The back of the terminal module PCB (printed circuit board) provides surface mount
pads which can be used to add serial and parallel components to any channel's signal
path. Figure 2-17 shows additional component locator information (see the
schematic and pad layout information on the back of the terminal module PCB).
Figure 2-18 shows some usage example schematics.
Upper layout also applies here
Lower layout also applies here
Figure 2-17. Additional Component Location
SH
HI
0 ohms
TO USER WIRING
LO SL
0 ohms
Default Circuit
SH
HI
0 ohms
TO USER WIRING
SL
LO
0 ohms
4 to 20 mA Sense
5 V full scale with 250 ohm (must use 16 volt range)
4 V full scale with 200 ohm (can use 4 volt range for better resolution)
Figure 2-18. Series & Parallel Component Examples
SCHEMATIC OF MODIFIABLE PARTS
HI HI
SH
TO VT1413C/VT1415A
LO LO
SL
COMP
LOCATOR
HI
HI
TO VT1422A
LO
LO
Normal Mode Low-Pass Filter Circuit
HI
TO VT1422A
LO
4-20 mA NOTE: input must not exceed common mode limits (usually
±16 volts unless attenuated with a VT1513A SCP)
Upper layout also applies here
Lower layout also applies here
COMP
LOCATOR
SH
HI
10 kohms
TO VT1422A
SL
LO
10 kohms
Chapter 2