Siemens FM 450-1 - Setting: Behavior of the Digital Outputs

Triggering hardware interrupts
You can also signalize the events over󹪞ow, under󹪞ow 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 a󹪜ected 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 󹪝rst 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 ...is enabled by
Q0 CTRL_DQ0
Q1 CTRL_DQ1
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 LED status Bit status
1Q0 (2Q0) is set CH 1 OUT 0 (CH2 OUT 0) is alight STS_COMP1 is set
1Q0 (2Q0) is reset CH 1 OUT 0 (CH2 OUT 0) is dark STS_COMP1 is reset
1Q1 (2Q1) is set CH 1 OUT 1 (CH2 OUT 1) is alight STS_COMP2 is set
1Q1 (2Q1) is reset CH 1 OUT 1 (CH2 OUT 1) is dark STS_COMP2 is reset
Modes, settings, parameters and commands
8.8 Setting: Behavior of the digital outputs
Counter module FM 450-1
Equipment Manual, 03/2022, A5E03648739-AC 65