Texas Instruments XTR108, User Manual

Page: 12 / 65

Hardware Overview
www.ti.com
12 SBOU123A – March 2012 – Revised September 2016
Submit Documentation Feedback
Copyright © 2012–2016, Texas Instruments Incorporated
XTR108EVM-USB Evaluation Board and Software Tutorial
2.2.1.9 J8 (RTD_CON)
Table 11 shows the signals connected to J8 on the Interface Board. J8 is used to connect the RTD
emulator circuit to an external XTR108 system.
Table 11. J8 Pinout (RTD_CON)
Pin Name Description
1 RCM R
CM
(common-mode resistor)
2 RZ R
Z
(zero-scale resistor)
3 RTD RTD resistance
2.2.2 Interface Board Jumper Settings
Table 12 explains the function of the XTR108EVM-USB Interface Board jumpers.
Table 12. Interface Board Jumper Functions
Jumper Default Description
JMP1 POT_RTD
This jumper selects which resistor string is used for the RTD emulator minimum-scale output.
Set the jumper to the POT_RTD position to use potentiometers POT1 and POT2. Set the
jumper to the R_RTD position to use surface-mount resistors R22-R24 (not installed by
default).
JMP2 POT_RTD
This jumper selects which resistor string is used for the RTD emulator mid-scale output.
Set the jumper to the POT_RTD position to use potentiometers POT3 and POT4. Set the
jumper to the R_RTD position to use surface-mount resistors R25-R27 (not installed by
default).
JMP3 POT_RTD
This jumper selects which resistor string is used for the RTD emulator maximum-scale output.
Set the jumper to the POT_RTD position to use potentiometers POT5 and POT6. Set the
jumper to the R_RTD position to use surface-mount resistors R28-R30 (not installed by
default).