Rockwell Automation 1747-PT1, D1747NP002 Hand-Held Terminal - Manual (Page 78)

Chapter 4
Data File Organization and Addressing
4–22
Monitoring Bit Instructions Having M0 or M1 Addresses
When you monitor a ladder program in the Run or Test mode, the following
bit instructions, addressed to an M0 or M1 file, are indicated as false
regardless of their actual true/false logical state.
When you are monitoring the ladder program in the Run or Test mode, the
HHT display does not show these instructions as being true when the
processor evaluates them as true.
] [
Mf:e.s
b
]/[
Mf:e.s
b
( )
Mf:e.s
b
(L)
Mf:e.s
b
(U)
Mf:e.s
b
f = file (0 or 1)
If you need to show the state of the M0 or M1 addressed bit, you can transfer
the state to an internal processor bit. This is illustrated below, where an
internal processor bit is used to indicate the true/false state of a rung.
This rung will not show its true rungstate because the EQU instruction is always shown as
true and the M0 instruction is always shown as false.
OTE instruction B3/2 has been added to the rung. This instruction shows the true or
false state of the rung.
EQU
EQUAL
Source A
N7:12
Source B N7:3
] [
B3
0
] [
B3
1
( )
M0:3.0
1
( )
M0:3.0
1
] [
B3
0
] [
B3
1
EQU
EQUAL
Source A
N7:12
Source B N7:3
( )
B3
2