Rockwell Automation 1760-xxxx Pico Controller User Manual - Manual (Page 88)

Publication 1760-UM001D-EN-P - September 2005
4-28 Draw a Circuit Diagram with Pico
Programming a Timing Relay
A timing relay is integrated into your circuit in the form of a contact.
The function of the relay is defined via the parameter display. The
relay is started via the trigger input TRG and can be reset via the reset
input RES. A timer also resets when it is turned off. To prevent
unpredictable switching states, use each coil of a relay only once in
the circuit diagram.
At least two elements are needed in the circuit diagram for a timing
relay:
• A relay contact in the contact field, in this case T2.
• A trigger coil in the coil field, in this case TT2.
You can also wire up the reset coil RT2 if you wish to use an external
reset signal. Enter the number of the relay contact T2 and press Ok.
The parameter set for timing relay T2 is displayed. Specify the
function of the relay.
Parameters for Timers
The parameter display for a timing relay is used to modify the
switching function, setpoint time and timebase units and to enable or
disable parameter access.
The coil terminals are not shown if you access the parameters via the
PARAMETER menu option. The actual time is only displayed in Run
mode. To view the actual time, call up the parameter display via the
power flow display or using the PARAMETER option.
I1---------TT2
I2---------RT2
T 2 --------{Q1
T2 X M:S +
01.500 I1
00.000
00.000
I2
T:
Task:
Turn on output Q1 1.5 min.
after actuation via I1.
Disable T2 via I2.
Circuit Diagram:
Parameter Display:
T1 S +
00.000 I1
30.000
00.000
I2
T:
Switch Function
Timebase Units
Current Value
Setpoint
Parameter Display