Setting: Behavior Of The Digital Outputs - Siemens FM 450-1 Equipment Manual

Triggering hardware interrupts
You can also signalize the events overflow, underflow and zero crossing by means of hardware
interrupts.
8.8

Setting: Behavior of the digital outputs

Introduction
You can store two comparison values (comparison value 1 and 2) for the counters on the
module; these are assigned to the respective digital outputs (comparison value°1: 1Q0 and 2Q0,
comparison value 2: 1Q1 and 2Q1). The comparison values are compared to the current counter
status. When the counter status reaches a comparison value, the relevant output can be set.
Comparison values 1 and 2
You enter the two comparison values in the DB of the FC CNT_CTRL (CMP_V1, CMP_V2) and
transfer them to the FM 450-1 by setting the bits T_CMP_V1 or T_CMP_V2 (see the section
"Assignment of the DB (Page 87)"). The count is not affected by this.
The comparison values must be within the limits of the respective count range. The comparison
value is interpreted according to the selected count range. If you give FFFF FFFF H, for example,
as the comparison value, the value is interpreted as 4 294 967 295 within the 0 to +32 bit count
range, and as -1 within the -31 to +31 bit count range.
Enabling the outputs
Before you can activate the outputs, you must first enable them by setting the appropriate bits
in the DB (see the section Assignment of the DB (Page 87)). If you reset one of these bits, the
associated output is disabled immediately even if you have assigned a pulse duration for them.
Output
Q0
Q1
Status of the outputs
You can identify the state of the two outputs from the green status LEDs and the relevant bits in
the DB.
Output status
1Q0 (2Q0) is set
1Q0 (2Q0) is reset
1Q1 (2Q1) is set
1Q1 (2Q1) is reset
Counter module FM 450-1
Equipment Manual, 03/2022, A5E03648739-AC
LED status
CH 1 OUT 0 (CH2 OUT 0) is alight
CH 1 OUT 0 (CH2 OUT 0) is dark
CH 1 OUT 1 (CH2 OUT 1) is alight
CH 1 OUT 1 (CH2 OUT 1) is dark
Modes, settings, parameters and commands
8.8 Setting: Behavior of the digital outputs
...is enabled by
CTRL_DQ0
CTRL_DQ1
Bit status
STS_COMP1 is set
STS_COMP1 is reset
STS_COMP2 is set
STS_COMP2 is reset
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