Programmer (HHP) User guide
Chapter 8
Using Basic Instructions
8–2
Branch Instructions
Mnemonic
Function
Code
Name Purpose Page
MPS
10 Memory Push Stores the rung state that is present immediately preceding the MPS instruction. 8–10
MRD 11 Memory Read Reads the rung state stored by the MPS instruction and resumes operation using
that rung state.
8–10
MPP 12 Memory Pop Removes the rung state stored by the MPS instruction, reads it, and resumes
operation using that rung state.
8–10
ANB 13 And Block Places two blocks of logic in series with each other (ANDs them). 8–12
ORB 14 Or Block Places two blocks of logic in parallel with each other (ORs them). 8–12
Timer/Counter Instructions
Mnemonic
Function
Code
Name Purpose Page
TON 0 Timer-On Delay Counts timebase intervals when the instruction is true. 8–16
TOF 1 Timer-Off Delay Counts timebase intervals when the instruction is false. 8–18
RTO 2 Retentive Timer Counts timebase intervals when the instruction is true and retains the
accumulated value when the instruction goes false or when power cycle occurs.
8–20
CTU 5 Count Up Increments the accumulated value at each false-to-true transition and retains the
accumulated value when the instruction goes false or when power cycle occurs.
8–24
CTD 6 Count Down Decrements the accumulated value at each false-to-true transition and retains
the accumulated value when the instruction goes false or when power cycle
occurs.
8–25
RES 7 Reset Resets the accumulated value and status bits of a timer or counter. Do not use
with TOF timers.
8–27
Basic instructions are used most commonly for relay replacement functions,
counting, and timing operations. These instructions, when used in
Instruction List (Boolean) programs, represent hardwired logic circuits used
for the control of a machine or equipment.
The basic instructions are separated into four groups: bit, branch, timer, and
counter. Before you learn about the instructions in each of these groups, we
suggest that you read the overview that precedes the group:
• Bit Instructions Overview
• Branch Instructions Overview
• Timer Instructions Overview
• Counter Instructions Overview
About Basic Instructions