Function relay types, Function relay types -19 – Rockwell Automation 1760-xxxx Pico Controller User Manual User Manual

Page 79

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Publication 1760-UM001D-EN-P - September 2005

Draw a Circuit Diagram with Pico 4-19

Use relay functions ’S’ and ’R’ only once per relay. If both coils are
triggered at the same time, priority is given to the coil further down in
the circuit diagram. This is shown in the preceding signal diagram in
section ’B’.

Function Relay Types

The function relays are used to simulate some of the devices used in
conventional relay control systems. Pico provides the following
function relay types:

A function relay is started via its relay coil or by evaluating a
parameter. It switches the contact of the function relay according to its
function and the set parameters. Current actual values are erased if the
power is turned off or if the unit is switched to Stop mode.

Exception: Retentive coils retain their signal (see Chapter 7).

IMPORTANT

A latched relay is automatically switched off if the
power fails or if the device is in Stop mode.
Exception: Retentive coils retain signal 1 (see What is
Retention? on
page 7-1).

I1-I2-------SQ1

...

...

I2----------RQ1

Circuit Diagram Symbol

Function Relay Type

Timing relay, on-delayed
Timing relay, on-delayed with random switching

Timing relay, off-delayed
Timing relay, off-delayed with random switching

Timing relay, single pulse
Timing relay, flashing

Counter relay, up/down counter

Time switch, weekday/time
(only in Pico models with real time clock)

Analog comparator relay
(only in Pico 24V dc models)

Text display

D

C

R

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