Appendix B; Mh941 Scan Head Pin Assignments - Metrologic Instruments MH941 Mode D'emploi

Appendix B

MH941 Scan Head Pin Assignments

Pin Signal Name
Flip Sense
1
Data
2
Decode LED
3
22
A square wave output signal that changes polarity
when the scan mirror drive circuit changes the
motor direction. The frequency is approximately
19 Hz to achieve a nominal 38 flips/scan per
second.
The polarity and mirror direction do not
Note:
necessarily change at the same time.
This is an open collector output capable of sinking
25 mA via an external pull up resistor connected
to a voltage not to exceed +20 VDC.
An output digital representation of the scanned bar
code. A low level represents a bar and a high level
represents a space.
This is an open collector output capable of
sinking 25 mA via an external pull up resistor
connected to a voltage not to exceed +20 VDC.
The scan head is equipped with LED and beeper
assemblies. A +5 VDC to 12 VDC input to the
head at this pin will light the green LED and if
oscillated at about 2 KHz, drive a beeper.
This should be supplied with no more than 30mA
of current.
Typically, this is used to indicate a decode has
occurred.
Function