5 Function blocks
5.27 PW, pulse width modulation
238
Control Relay easy800
11/11 MN04902001Z-EN
www.eaton.com
Parametric programming of the function block inputs/outputs
When using the function block in the circuit diagram for the first time, use
OK to automatically enter the general display of function block parameters,
as shown in the figure on the left. Enter the function block settings here.
The display contains the following elements:
You can assign the following operands to function block inputs SV and PD to
ME:
•
Constant
•
Markers MD, MW, MB
•
Analog inputs IA01 to IA04:
•
IA01: Terminal I7
•
IA02: Terminal I8
•
IA03: Terminal I11
•
IA04: Terminal I12
•
Analog output QA01
•
Output
…
QV> of a different function block
Function of the function block
If the function block is enabled by 1 at the PW..EN coil, the set value at input
SV is transformed into a pulse sequence with a constant period duration
(PD). The pulse width (PW) is therefore proportional to the manipulated
variable (SV). The period duration and the minimum on time can be selected
as required within the set limits.
Figure 173:Pulses at the function block output
PW: Pulse width
PD: Pulse duration
ME: Minimum on duration, Minimum off duration
PW01 +
>SV
>PD
>ME
PW01
Function block; Data multiplexer, number 01
+
Parameter set can be called via the PARAMETERS menu
>SV
Manipulated variable: 0 - 4095
>PD
Period duration: 5 - 65535 ms
>ME
Minimum on time = Minimum off time: 1 - 65535 ms
0
1
PD
ME
PW
PW
