Description
(Original Document)
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Description of the Function
The MV_DIA DFB can monitor:
Additional parameters EN and ENO can be configured.
NOTE: This diagnostic DFB cannot be used in a user DFB.
Representation in FBD
Representation:
Representation in LD
Representation:
Representation in IL
Representation: 
CAL MV_1 (ED := Enable_Control, ENABLE := Enable_COND, EVENT := Event_Input, COND := Cond_Input, EVENT_T0 := Event_T0_Input, EVENT_T1 := Event_T1_Input, ERROR => Error_Output, STATUS => Status_Output, TTIME => Time_Output)
Representation in ST
Representation: 
MV_1 (ED := Enable_Control, ENABLE := Enable_COND, EVENT := Event_Input, COND := Cond_Input, EVENT_T0 := Event_T0_Input, EVENT_T1 := Event_T1_Input, ERROR => Error_Output, STATUS => Status_Output, TTIME => Time_Output);
Description of Parameters
The following table describes the input parameters:
Parameter
Type
Description
ED
EBOOL
DFB activation bit.
If ED = 0, the EVENT,EVENT_T0, EVENT_T1 and COND inputs are not monitored.
The default value is 0.
ENABLE
EBOOL
Monitor enable bit
If ENABLE = 0, only COND input is monitored.
If ENABLE = 1, the CONDand EVENT_T0, EVENT_T1 are monitored.
The default value is 0.
EVENT
EBOOL
Input bit to be monitored.
If the DFB is executed and ENABLE = 1, the DFB verifies that the EVENT input:
  • possesses the value specified by the VALUE public variable,
  • is stable (no switching between 1, 0, 1 state ).
  • possesses the value specified by the VALUE public variable, a MMIN minimum time and a MMAX maximum time.
If this is not the case, the DFB will signal that there is a fault.
If ENABLE = 0, theEVENT input is not monitored.
The default value is 0.
COND
EBOOL
Input bit to be monitored.
The input bit to be monitored is set at 1, whatever the status of the ENABLE input.
If the DFB is executed and this bit changes to 0, the DFB will signal that there is a fault.
The default value is 1.
EVENT_T0
EBOOL
Exterior event associated with T0 time.
This (optional) parameter is a bit which must change from 0 to 1 before T0 time or in ENABLE = 1 format.
The default value is 1.
EVENT_T1
EBOOL
Exterior event associated with T1 time.
This (optional) parameter is a bit which must change from 0 to 1 before T1 time or in ENABLE = 1 format.
The default value is 1.
The following table describes the output parameters:
Parameter
Type
Description
ERROR
EBOOL
Fault bit
This bit is set to 1 as soon as a fault appears.
This bit is set to 0 if the ED input returns to 0 or if there is no longer an error.
STATUS
INT
Fault type.
The following bits indicate the type of fault detected :
  • bit 0 =1: EVENT is different from the VALUE specified,
  • bit 1 =1: COND does not possess the expected value of 1,
  • bit 2=1: EVENT does not possess the VALUE value during the MIN period requested,
  • bit 3 =1: EVENT possesses the value VALUE beyond the MAX time requested,
  • bit 4 =1: EVENT_T0 not seen at 1 before the T0 time requested,
  • bit 5 =1: EVENT_T1 not seen at 1 before the time T1 requested,
  • bit 6 =1: EVENT_T0 not seen at 1 during range ENABLE=1,
  • bit 7 =1: EVENT_T1 not seen at 1 during range ENABLE=1,
  • bit 8 =1: EVENT is unstable,
  • bit 9 =1: EVENT_T0 falls back to 0 after T0 time,
  • bit 10 =1: EVENT_T1 falls back to 0 after T1 time,
  • bit 14 =1: fault through the overrunning of the internal clock.
This word is set at 0 if there is no fault.
This word is set at 0 if the ED input returns to 0 or if there is no longer an error.
TTIME
INT
Current time.
Word indicating the current time with a time base expressed in multiples of N x 100 ms
The N coefficient is defined by the BASE public variable.
TTIME is initialized at the PPRESET value, and starts to change on the rising edge of the ENABLE input.
It sets to 0, on the ENABLE falling edge.
If a fault is detected (caused by EVENT input), TTIME does not remain frozen:
  • if ENABLE = 0, TTIME = 0
  • if ENABLE = 1, TTIME = internal running time