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ifm
Programming Manual (supplement) CAN module RTC CR3020
2017-10-26
ifm function elements
ifm functional elements, POUs (Classic)
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3.3.4
RTC_REQUEST
21878
Unit type = function block (FB)
Unit is contained in the library
ifm_RTC_Classicx_V01yyzz.LIB
(x = 1...n = number of the CAN interface (depending on the device,
→ data sheet))
Symbol in CODESYS:
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Description
21864
RTC_REQUEST enables to request the current time, date and day of the week of the real-time clock
(RTC). Additionally, this POU warns about a low battery level.
With the identifier (0x200 + node ID), the controller sends an empty message (without data) to the bus
in order to request the current data.
The real-time clock responds to this with the identifier (0x180 + node ID).
For this, the real-time clock sends a matrix with the following content:
calendar day, month, year, hour, minute, second as well as day of the week and battery status
The function assigns this data to the corresponding output parameters.
The output parameter RESULT informs about the current operating status of the POU.
We recommend executing this POU e.g. at 200 ms intervals. This is how it is ensured that your
application always has up-to-date data.
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Parameters of the inputs
21881
Parameter
Data type
Description
INIT
BOOL
TRUE (only for 1 cycle):
Function block is initialised
FALSE:
during further processing of the program
REQUEST
BOOL
TRUE:
execute this function element
Request data
FALSE:
unit is not executed
NODE_ID
BYTE
Node number of the addressed CAN participant