Input Description¶
SLOT
| Data_Type | Default_Value | Range | Unit |
|---|---|---|---|
| BYTE | - | - | - |
This input is used to select the slot (module number) of the DC541.
The slots are numbered consecutively from right to left. Slot 1 is the first slot on the left of the CPU.
CH (channel)
| Data_Type | Default_Value | Range | Unit |
|---|---|---|---|
| BYTE | - | 0-7 for the inputs C0-C7 | - |
CH is used to select the channel for time and frequency measurement. If an invalid value is entered at input CH or if the selected channel is not configured as 32 bit count-up counter (FWD_CNT), the function flock is aborted with DONE = ERR = TRUE and an error is displayed.
EN_VISU (enable \ input in visualization)
| Data_Type | Default_Value | Range | Unit |
|---|---|---|---|
| BOOL | - | - | - |
If this input is TRUE, it is possible to control the function block inputs (except SLOT, CH and EN_VISU) via the integrated visualization of the function block. If input EN_VISU = FALSE, control via the visualization is disabled and the labelling of the corresponding control elements is displayed in gray. The actual values are always displayed.
EN (enable)
| Data_Type | Default_Value | Range | Unit |
|---|---|---|---|
| BOOL | - | - | - |
In order to enable pulse counting for input CH, input EN has to be continuously TRUE. The Function Block is not processed if input EN = FALSE.
When the function block is called for the first time, the inputs are checked for validity and plausibility and the corresponding device is checked for correct configuration in the operating mode “counting mode”. If this is not the case, processing is aborted.
SET
| Data_Type | Default_Value | Range | Unit |
|---|---|---|---|
| BOOL | - | - | - |
At a rising edge at this input, the counter is set to the value of input CNT_SET. Counting is enabled after reset process though SET = TRUE.
EN_LIM (enable \ limit)
| Data_Type | Default_Value | Range | Unit |
|---|---|---|---|
| BOOL | - | - | - |
Input EN_LIM is used to set the operating mode for the counter:
EN_LIM = FALSE: Infinite counter (endless mode).
EN_LIM = TRUE: Limiting counter (limit mode).
Switching between the operating modes can be done during running operation. And it is possible to change the upper limit value LIM_MAX and the lower limit value LIM_MIN during running operation. LIM_MAX has to be higher than LIM_MIN. If LIM_MIN is higher than LIM_MAX, an error is displayed.
In case of a rising edge at input EN_LIM (transition from endless mode to limit mode), the present counter value can change depending on the values of LIM_MIN and LIM_MAX.
| Present counter value | Changed counter value |
|---|---|
| ACT_CNT < LIM_MIN | ACT_CNT := LIM_MIN |
| LIM_MIN <= ACT_CNT <= LIM_MAX | ACT_CNT := ACT_CNT (no change) |
| ACT_CNT > LIM_MAX | ACT_CNT := LIM_MIN |
LIM_MAX (limit \ maximum)
| Data_Type | Default_Value | Range | Unit |
|---|---|---|---|
| DWORD | - | - | - |
LIM_MAX is used to set the upper limit value for the counter. LIM_MAX has to be higher than the lower limit value LIM_MIN. If LIM_MIN is higher than LIM_MAX, an error is displayed.
LIM_MIN (limit \ minimum)
| Data_Type | Default_Value | Range | Unit |
|---|---|---|---|
| DWORD | - | - | - |
LIM_MIN is used to set the lower limit value for the counter. The upper limit value LIM_MAX has to be higher than LIM_MIN. If LIM_MIN is higher than LIM_MAX, an error is displayed.
CNT_SET (counter set)
| Data_Type | Default_Value | Range | Unit |
|---|---|---|---|
| DWORD | - | - | - |
CNT_SET is used to adjust the counter set value.
If input SET = TRUE, the counter is set to the value of input CNT_SET and remains at this value as long as input SET = TRUE. Counting is enabled again with the occurrence of the falling edge at input SET.
In case of a reference point approch (EN_REF = TRUE), the rising edge on channel C2 causes the actual value of the counter (ACT_CNT) to be adjusted to the set value CNT_SET.
A FALSE -> TRUE edge at input EN activates the status polling. If the value at input SLOT is not valid, processing is aborted and an error is displayed. The function block outputs are updated as long as input EN = TRUE. The function block processing has been completed successfully, if output DONE changes to TRUE. During the processing of a request, state changes at input EN are recognized but not evaluated.