ZU25102A_e.DOC / Mrz-08
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1.
Introduction
ZU 251 represents a small and low-cost, but highly performing converter for industrial
applications, where incremental counting of positions or events must be converted to either
analogue format or serial data. The unit has been designed as a compact module with 12 screw
terminals and a 9-position SUB-D connector (female). The housing is suitable for standard DIN
rail mounting.
The impulse input side provides channels A, B and also the inverted lines /A, /B which must be
used with TTL/ RS422 input signals. The unit can count and convert the following formats to
analogue and serial:
a. Up/down count with quadrature input (A/B, 90
°
).
The polarity of the analogue output and the sign of the serial data depend on the sign of
the actual counting result
b. Single channel impulses on channel A.
Input B sets the counting direction and therefore also the polarity of the output
(LOW = negative, HIGH = positive).
Please observe:
•
Open NPN inputs are HIGH
•
Open PNP inputs are LOW
•
Open RS422 inputs are HIGH
c. Dual count of fully independent events on channels A and B, where the output signal
represents the sum or the difference of both counts.
A
B
A
B
A
B
A and B, quadrature 90°
A=impulse, B=static direction signal
A and B: independant counting events
a.
b.
c.
+
-
The definitions for “zero analogue output” and “full scale analogue output” definition can be
set over the full counting range of +/-8 decades (-99 999 999 to +99 999 999)
