Rockwell Automation 1760-xxxx Pico GFX-70 Controllers User Manual - Manual (Page 113)

Publication 1760-UM002B-EN-P - March 2005
Wiring with Pico GFX-70 4-3
Program
A program is a sequence of commands which the Pico GFX-70 executes
cyclically in RUN mode. A Pico GFX-70 program consists of the necessary
settings for the device, the Pico-Link, Serial Interface, password, system
settings, a circuit diagram and/or function blocks and/or the visualization
screens.
The circuit diagram is that part of the program where the contacts are
connected together. In RUN mode a coil is switched on and off in accordance
with the current flow and the coil function specified.
Function Blocks
Function blocks are program elements with special functions. Example: timing
relays, time switches, arithmetic function blocks. Function blocks are elements
provided with or without contacts and coils as required. In RUN mode the
function blocks are processed according to the circuit diagram and the results
are updated accordingly.
Examples:
Timing relay = function block with contacts and coils
Time switch = function block with contacts
Visualization Screens
Visualization screens are the sections of programs containing the display and
operator functions.
Relays
Relays are switching devices which are electronically simulated in Pico
GFX-70. They actuate their contacts according to their designated function. A
relay consists of a coil and at least one contact.
Contacts
You modify the current flow with the contacts in the Pico GFX-70 circuit
diagram. Contacts such as make contacts carry a 1 signal when closed and 0
when open. Every contact in the Pico GFX-70 circuit diagram can be defined
as either a make contact or a break contact.