Motorola MT2090 用户手册

Maintenance and Troubleshooting 15 - 5

Device emits aiming pattern, but 
does not decode the bar code.

Device is not programmed for the 
correct bar code type.

Program the device to read that type of 
bar code. See 

.

Bar code symbol is unreadable.

Scan test symbols of the same bar 
code type to determine if the bar code 
is defaced.

The symbol is not completely inside 
aiming pattern.

Move the symbol completely within the 
aiming pattern.

Scan window may be dirty.

Clean the scan window.

Device does not boot when a 
USB cable is attached.

The device’s battery is discharged.

Normal behavior if the battery is 
severely discharged. The battery must 
charge at a reduced charge rate until 
the battery acquires sufficient charge to 
boot the device. This can take up to two 
hours, depending on the level of battery 
discharge.

Device is attached to a host PC 
via USB cable; PC register 
boots up after being powered 
down for an extended period of 
time; device does not boot.

When the host is powered down, the 
device remains powered from its 
battery. This can result in a completely 
discharged battery.

See above.

Device emits short low/short 
medium/short high beep 
sequence (power-up beep 
sequence) more than once.

The USB bus may put the device in a 
state where power to the device is 
cycled on and off more than once.

Normal during host reset.

Device emits 4 short high beeps 
during decode attempt.

Device has not completed USB 
initialization.

Wait several seconds and scan again.

Device emits high/high/high/low 
beeps when not in use.

RS-232 receive error.

Normal during host reset. Otherwise, 
set the device's RS-232 parity to match 
the host setting.

Device emits low/high beeps 
during programming.

Input error or Cancel bar code was 
scanned.

Scan the correct numeric bar codes 
within range for the parameter 
programmed.

Device emits low/high/low/high 
beeps during programming.

Out of ADF parameter storage space.

Erase all rules and re-program with 
shorter rules.

Device emits a power-up beep 
after changing USB host type.

The USB bus re-established power to 
the device.

Normal when changing USB host type.