Appendix A
Appendix D
Special Relays
D–2
Special Relays
DL05 PLC Special Relays
“Special Relays” are just contacts that are set by the CPU operating system to
indicate a particular system event has occurred. These contacts are available for
use in your ladder program. Knowing just the right special relay contact to use for a
particular situation can save lot of programming time. Since the CPU operating
system sets and clears special relay contacts, the ladder program only has to use
them as inputs in ladder logic.
SP0
First scan
on for the first scan after a power cycle or program to run transition
only. The relay is reset to off on the second scan. It is useful where a
function needs to be performed only on program startup.
SP1
Always ON
provides a contact to insure an instruction is executed every scan.
SP3
1 minute clock
on for 30 seconds and off for 30 seconds.
SP4
1 second clock
on for 0.5 second and off for 0.5 second.
SP5
100 ms clock
on for 50 ms. and off for 50 ms.
SP6
50 ms clock
on for 25 ms. and off for 25 ms.
SP7
Alternate scan
on every other scan.
SP11
Forced run
mode
on when the mode switch is in the run position and the CPU is
running.
SP12
Terminal
run mode
on when the CPU is in the run mode.
SP13
Test
run mode
on when the CPU is in the test run mode.
SP15
Test
stop mode
on when the CPU is in the test stop mode.
SP16
Terminal
PGM mode
on when the mode switch is the the TERM position and the CPU is in
program mode.
SP17
Forced stop
on when the mode switch is in the STOP position.
SP20
Forced
stop mode
on when the STOP instruction is executed.
SP22
Interrupt enabled on when interrupts have been enabled using the ENI instruction.
Startup and
Real-Time Relays
CPU Status Relays
Summary of Contents for DL05
Page 1: ...DL05 User Manual Automationdirect com ...
Page 2: ...DL05 User Manual Automationdirect com ...
Page 436: ...1B DL05 Error Codes In This Appendix Ċ Error Code Table ...
Page 443: ...1C Instruction Execution Times In This Appendix Ċ Introduction Ċ Instruction Execution Times ...
Page 459: ...1D Special Relays In This Appendix Ċ DL05 PLC Special Relays ...
Page 464: ...1E DL05 Product Weights In This Appendix Ċ Product Weight Table ...
