Microscan MS-4X Instrukcja Użytkownika Pobierz pdf (Strona 73)

Chapter 4 Read Cycle/Trigger

MS-880 Industrial Long Range Scanner User’s Manual 4-7

4–Read Cycle/Trig-

External Trigger Edge

Important: Level and Edge apply to the active logic state (Active Off (I

OFF

) or

Active On (I

)) that exists while the object is in a read cycle, between the rising

edge and falling edge. Rising edge is the trigger signal associated with the appearance

of an object. Falling edge is the trigger signal associated with the subsequent disap-

pearance of the object.

Note: In External Trigger Edge, sending a Non-delimited Start Serial Character

will start a read cycle; however a Non-delimited Stop Serial Character has no

effect. See “Start and End Trigger Characters (non-delimited)” on page 4-10.

Definition: External Trigger Edge, as with Level, allows the read cycle (active

state) to begin when a trigger (change of state) from an external sensing

device is received. However, the passing of an object out of sensor range

does not end the read cycle. The read cycle ends with a good read output

or, depending on End of Read Cycle setting, a timeout or new trigger

occurs.

Usage: This mode is highly recommended in any application where conveying

speed is constant or if spacing, object size, or timeouts are consistent.

Serial Cmd: <K200,3>

Figure 4-2 Trigger Edge

Initiate Read Cycle:

Object # 1, moving in front of the detector

beam, causes a change in the trigger state,

initiating the read cycle.

Initiate Second Read Cycle:

Object # 2, moving in front of the detector

beam, causes another change in the trigger

state. This signal initiates a new read cycle

and ends the previous read cycle unless

Timeout is enabled and a good read or tim-

eout has not occurred.

Associated waveforms assume

External Trigger State is set

to Active On.

1 2 ... 68 69 70 71 72 73 74 75 76 77 78 ... 311 312

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Microscan MS-4X Instrukcja Użytkownika Strona 73