3M™MicroTouch™ System DST2270DX Integration Guide
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3M Touch Systems, Inc. Proprietary Information – TSD-25739
EMI Considerations
The DX123 controller meets FCC and EU emissions Class A standards. If Class B is
required, the controller must be mounted behind a metal cover with just the sensor flex
tail exiting to the display (no shield is required on the flex tail). This metal cover can be
part of the housing for the display. Some displays have an internal metal cover and a
plastic outer housing and some use a metal cover as the outer rear cover. Mounting the
controller inside either metal cover should be sufficient to meet Class B.
Handling and ESD Protection
Note:
When handling the 3M™ MicroTouch™ DST2270 sensor and associated
electronics make sure you wear an ESD strap to prevent electrostatic discharge to
electrical components on the sensor.
When mounting the sensor and controller, use normal precautions for handling
electrostatic sensitive devices. The DX123 controller has internal protection to ±20 kV
for ESD air discharges to the sensor (not to the controller directly) that may occur during
normal operation of the sensor. Refer to Appendix A for more detailed specifications.
Establishing the Data Connection
The DX123 controller can operate in either USB or serial mode – no need for different
controllers. You cannot operate in both modes at the same time. If you try to connect
both USB and serial cables, the controller will default to USB mode only.
USB Connection
In USB mode, the controller uses a 3M Touch Systems USB communication cable (P/N
7319420) PC 99 compatible or equivalent interconnect. One end of this cable plugs into
the USB connector (J103) on the DX123 controller. The other end has a Type-A
connector, and plugs into a USB port on your PC.
When creating a custom cable, use the Molex 51004-0500 mating connector. The
following table describes the interconnections of the 3M Touch Systems USB cable.
USB Cable for DX123 Controllers
PC Side (USB Type A)
Wire
Controller Side (5-Pin Molex)
Pin
USB Assigned
Color
Pin
Description
1
+5Vdc (VBUS)
Red
1
+5Vdc VBUS power
2
Data (DN)
Gray
2
Data (DN) differential pair
3
Data (DP)
Green
3
Data (DP) differential pair
4
0V
Black
4
Power return
5
Cable Shield Shell
Charcoal
Gray
5
Outer cable shield around signal
and power lines. Chassis (earth)
ground
