Intermec 073290-001 User Manual

Standard asynchronous serial signals TxD, RxD, RTS and CTS are 
multiplexed onto the 10-pin scanner connector as shown in the “Tethered 
Scanner Signal Descriptions” table on page 84, and routed through the 
FPGA. 

SCAN_RTS and SCAN_CTS are accessed by software through memory-
mapped FPGA registers when the FPGA scanner interface is configured 
for serial scanners. SCAN_TXD and SCAN_RXD are routed through the 
FPGA to the “ST” UART on the PXA255. The operating system maps 
this UART as COM3. 

3.3V and 5V scanner power is controlled through HCR register U11 
output SCAN_PWR_EN*. The 22-pin scanner port supports only 3.3V 
scanner power. The 16-pin scanner port supports both 3.3V and 5V 
power. SCAN_PWR_EN* switches both supplies on and off 
simultaneously through high-side switches U12 and U13; the voltage 
appropriate to the installed scanner is selected through the scanner flex 
wiring. A loopback pin on the connector feeds the selected voltage back to 
the interface’s pull-up resistors. 

5V power for tethered scanners attached through the docking connector 
(TETH_SCAN_VCC) is controlled by HCR register U11 output 
DOCK_EN through high-side switch U13. 

Decoded-output tethered scanners and undecoded (DBP) tethered 
scanners are supported through an optional 10-pin Stewart connector built 
onto a flex circuit that plugs into 16-pin scan port J3. 

•  Undecoded tethered scanners use the FPGA count gathering interface 

•  Decoded scanners are supported as serial (TTL-level RS-232) devices 

(See “Serial (RSTTL) Scanner Interface” on page 82). 

•  Decoded scanners may also be supported as wand emulation or laser 

emulation devices (see “Wands and Wand Emulation” on page 80), but 
serial is preferred to minimize power consumption, and avoid speed and 
buffer size limitations. 

Laser interface and TTL-level serial signals are supported at the 10-pin 
Stewart connector using Intermec’s standard pin-out (except that no 
battery power is provided on pin 10):