Edge Sync Mode; Envelope Sync Mode - Hand Held Products SV Series User Manual

Edge Sync Mode

This mode senses a signal transition level of a sync signal as shown below.
The illustration above shows the sync operation of an SV unit programmed to
sense the rising edge of a sync signal in edge mode. Each time a rising edge is
sensed, the SV unit does the following:
1. It verifies that at least the number of bar codes expected (programmed)
since receiving the last sync input have been fully decoded. If not, a No
Read condition is internally set for possible reporting through communication
or output activation.
2. It begins a new interval, counting the bar codes analyzed until the next sync
input is received.
3. A serial communication report is transmitted and an output port is updated
per its programmed function each time a bar code is analyzed.

Envelope Sync Mode

This mode senses two transitions (leading and trailing) of the sync signal to
determine when to begin and end the period for determining missing bar codes:
Sync period starts here
Sync period ends here
The illustration above shows the sync operation of an SV unit programmed to
sense the rising voltage edge as the start of a sync period. The SV unit operates
in this mode as follows:
1. Upon receipt of the starting edge of a sync signal, the unit begins counting
the bar codes being scanned and analyzed.
2. A serial communication report is transmitted, and an output port is updated
per its programmed function each time a bar code is analyzed.
2 - 4
Sync sensed here
Quick Check® SV Series User's Guide