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BasicController CR0403
TIMER_READ_US
Unit type = function block (FB)
Unit is contained in the library ifm_CR0403_Vxxyyzz.LIB
Symbol in CODESYS:
35040
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Description
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TIMER_READ_US reads the current system time in [µs].
When the supply voltage is applied, the device generates a clock pulse which is counted upwards in a register. This register can be read by means of the FB call and can for example be used for time measurement.
Info
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The system timer runs up to the counter value 4 294 967 295 µs at the maximum and then starts again from 0.
4 294 967 295 µs = 1h 11min 34s 967ms 295µs
Parameters of the outputs
35086
Parameter
TIME_US
RESULT
Data type
DWORD
BYTE
Description current system time [ s] feedback of the function block
(possible messages → following table)
Possible results for RESULT:
Value dec | hex
Description
0
1
00
01
FB is inactive
FB execution completed without error
– data is valid
200
BasicController CR0403
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6 Diagnosis and error handling
Content
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The runtime-system (RTS) checks the device by internal error checks:
• during the boot phase (reset phase)
• during executing the application program
→ chapter Operating states
In so doing a high operating reliability is provided, as much as possible.
6.1 Diagnosis
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During the diagnosis, the "state of health" of the device is checked. It is to be found out if and what
→faults are given in the device.
Depending on the device, the inputs and outputs can also be monitored for their correct function.
- wire break,
- short circuit,
- value outside range.
For diagnosis, configuration and log data can be used, created during the "normal" operation of the device.
The correct start of the system components is monitored during the initialisation and start phase.
Errors are recorded in the log file.
For further diagnosis, self-tests can also be carried out.
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6.2 Fault
28834
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A fault is the state of an item characterized by the inability to perform the requested function, excluding the inability during preventive maintenance or other planned actions, or due to lack of external resources.
A fault is often the result of a failure of the item itself, but may exist without prior failure.
In →ISO 13849-1 "fault" means "random fault".
6.3 Response to system errors
35831
In principle, the programmer is responsible to react to the error messages in the application program.
An error description is provided via the error message.
> The system resets the error message as soon as the error causing state is not present anymore.
201
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BasicController CR0403
6.3.1 Example process for response to an error message
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The runtime system cyclically writes the system flag TEMPERATURE.
The application program detects the device temperature by retrieving the INT variable.
If permissible values for the application are exceeded or not reached:
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The application program deactivates the outputs.
► Rectify the cause of the error.
> The application program detects the temperature value which has returned to normal:
The machine / system can be restarted or operation can be continued.
6.4 CAN / CANopen: errors and error handling
→ System manual "Know-How ecomat mobile "
→ chapter CAN / CANopen: errors and error handling
35698
28808
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BasicController CR0403
7 Appendix
Content
28796
Additionally to the indications in the data sheets you find summary tables in the appendix.
7.1 System flags
The addresses of the system flags can change if the PLC configuration is extended.
► While programming only use the symbol names of the system flags!
System flags (symbol name)
SUPPLY_VOLTAGE_VBBx
SUPPLY_VOLTAGE_VBBS
SUPPLY_VOLTAGE_VU
Type
WORD
WORD
WORD
INT
Description supply voltage on VBBx in [mV]
CR040n: x = 1, 2
CR041n: x = 1, 2
CR253n: x = 1, 2 supply voltage on VBBs in [mV] internal supply voltage in [mV]
Temperature in the device in [°C] TEMPERATURE
35784
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