# Fan2Speed
## `Fan2Speed` (FB)
FUNCTION\_BLOCK Fan2Speed
### Short description
> Control of a two-speed fan\
> Additional functions: air shortage monitoring, operation monitoring, maintenance switch, manual override, status display\
> Typical application: control of a fan
### Representation
### Function description
#### General
This function block controls a single-stage fan.\
The following function blocks are essentially used:
* AirShortage
* ManBin
* OperatingHours
#### Release - fan before manual override *xAB*
The release - fan before manual override *xAB* is influenced by the fan request *xEn*, the collective fault indication *xAlarm*, the maintenance switch indication *xMSwitch*, the parameter **xAlarmControl** and the air shortage monitoring.\
\
The release - fan before manual override *xAB* is active (= TRUE) if the following conditions are present simultaneously:\
\
Case 1:\
\
\&#xNAN;*xEn* = TRUE (request active)\
\&#xNAN;*xMSwitch* = TRUE (motor protection switch not tripped)\
**xAlarmControl** = FALSE (collective fault indication not considered)\
\
Case 2:\
\
\&#xNAN;*xEn* = TRUE (request active)\
\&#xNAN;*xAlarm* = FALSE (collective fault indication not active)\
\&#xNAN;*xMSwitch* = TRUE (motor protection switch not tripped)\
**xAlarmControl** = TRUE (collective fault indication considered)\
\
In all other situations the release - fan before manual override *xAB* not active (= FALSE).
#### Release - fan after manual override *xHB*
The release - fan before manual override *xHB* corresponds to the release - fan before manual override *xAB*, additionally extended by a manual override module and by a forced override.
| *xAB* | **eManModeB** | *xForce* | **xForceOption** | *xHB* | Notes |
| ----- | -------------- | -------- | ---------------- | ----- | ---------------------------------------------- |
| FALSE | eMANBIN.Auto | FALSE | X | FALSE | Manual override module in automatic |
| TRUE | eMANBIN.Auto | FALSE | X | TRUE | Manual override module in automatic |
| X | eMANBIN.ManOn | FALSE | X | TRUE | Manual override module in manual operation On |
| X | eMANBIN.ManOff | FALSE | X | FALSE | Manual override module in manual operation Off |
| X | X | TRUE | FALSE | FALSE | Forced override Off |
| X | X | TRUE | TRUE | TRUE | Forced override On |
Legend: X = any
#### Maintenance switch indication *xMSwitch*
*xMSwitch* = TRUE: maintenance switch has not been triggered (normal state)\
\&#xNAN;*xMSwitch* = FALSE: maintenance switch has been triggered (fault state)
#### Forced override *xForce*
The forced override acts directly on the output *xHB*. The parameter **xForceOption** determines which state the output *xHB* assumes when TRUE at the input *xForce* .
#### Operating hours and switching cycles
The number of operating hours and switching cycles are recorded (= counting process active) if the fan running indication *xFb* is active and at the same time the collective fault indication *xAlarm* is not active (= FALSE).\
The results are available at the counter outputs **udiOperatingHours** and **udiCountFb** available.
> **Write access to the counter values**
>
> Via the path 'InstanceName.\_OperatingHours.udiOperatingHours' or 'InstanceName.\_OperatingHours.udiCountFb' write access to both counters is possible.
#### Date / time of the last operation of the fan *dtLastFb*
At the output *dtLastFb* the current date / time is available during the counting process.\
At the output *dtLastFb* the date / time at the end of the last counting process is available outside the counting process.\
At the output *dtLastFb* the initialization value DT#1970-1-1-0.0.0 is output before the first counting process.
#### Operating monitoring
The operating monitoring can be enabled (= TRUE) or disabled (= FALSE) by the setpoint / parameter **xFbControl** When monitoring is disabled the operating monitoring fault indication *xAlarmFb* is always disabled (= FALSE).\
When monitoring is enabled the operating monitoring fault indication *xAlarmFb* is activated (= TRUE) if the following conditions are present simultaneously for a minimum duration **udiFbControlTime** as follows:\
\
\&#xNAN;*xHB* and *xFb* = not equal (enable state and operating state do not match)\
\&#xNAN;*eAOO* = HVACTYPES.eManBin.Auto (manual override - hardware in automatic)\
\&#xNAN;*xFbControl* = TRUE (operating monitoring is enabled)\
\
The operating monitoring fault indication *xAlarmFb* is reset (= FALSE) if at least one of the following conditions is met:\
\
\&#xNAN;*eAOO* = HVACTYPES.eManBin.Auto (switch back to automatic operation of the manual override - hardware)\
\&#xNAN;*xQuit* = TRUE (reset of fault indications is active)\
\&#xNAN;*xFbControl* = FALSE (operating monitoring disabled)
#### Air shortage monitoring
It serves to detect an air shortage situation by evaluating the signals at the inputs air shortage indication *xPFb* and the fan running indication *xFb*.\
The air shortage monitoring can be enabled (= TRUE) or disabled (= FALSE) by the setpoint / parameter **xPFbControl** In the disabled state the output - fault indication *xAlarmPFb* is not activated (= FALSE).\
\
The output - fault indication *xAlarmPFb* is activated (*xAlarmPFb* = TRUE) if the conditions 1 and 2 below are both met simultaneously.\
\
Condition 1: The input for the differential pressure switch *xPFb* remains for at least the waiting time *udiPFbControlTime* permanently in the state FALSE (= air shortage situation).\
\
Condition 2: The running indication for the fan *xFb* remains for at least the waiting time *udiPFControlTime* remains permanently in the state TRUE (= fan in operation).\
\
\
The output - fault indication *xAlarmPFb* is deactivated in the following cases (*xAlarmPFb* = FALSE):\
\
Case 1: Conditions 1 and / or 2 are not met and the reset of the fault indication *xQuit* is active (= TRUE).
#### Collective fault indication *xAlarm*
The collective fault indication is activated (= TRUE) if at least one of the following described conditions is met.\
\
\&#xNAN;*xAlarmIn* = TRUE (fan fault indication is active)\
\&#xNAN;*xAlarmFB* = TRUE (error from the operating monitoring)\
\&#xNAN;*xAlarmPFb* = TRUE (error from the air shortage monitoring)\
\&#xNAN;*xMSwitch* = FALSE (maintenance switch has been triggered)\
\
In all other cases the collective fault is not active (= FALSE).
#### Collective automatic-mode message *xAuto*
The collective automatic-mode message *xAuto* is activated (= TRUE) if the input *eAOO* has the value HVACTYPES.eManBin.Auto and the setpoint / parameter **eManModeB** has the value eMANBIN.Auto.\
In all other cases the collective automatic-mode message *xAuto* is not activated (= FALSE).
### CODESYS
InOut:
| Scope | Name | Type | Initial |
| ----------- | --------------------- | ------- | ------------ |
| Input | `xEn1` | `BOOL` | |
| Input | `xEn2` | `BOOL` | |
| Input | `xForce` | `BOOL` | FALSE |
| Input | `xFb1` | `BOOL` | |
| Input | `xFb2` | `BOOL` | |
| Input | `xPFb` | `BOOL` | |
| Input | `xMSwitch` | `BOOL` | TRUE |
| Input | `xAlarmIn1` | `BOOL` | |
| Input | `xAlarmIn2` | `BOOL` | |
| Input | `eAOO1` | eManBin | eManBin.Auto |
| Input | `eAOO2` | eManBin | eManBin.Auto |
| Input | `xQuit` | `BOOL` | FALSE |
| Output | `xHB1` | `BOOL` | |
| Output | `xHB2` | `BOOL` | |
| Output | `xAB1` | `BOOL` | |
| Output | `xAB2` | `BOOL` | |
| Output | `xAlarmFb` | `BOOL` | |
| Output | `xAlarmPFb` | `BOOL` | |
| Output | `dtLastFb` | `DT` | |
| Output | `udiOperatingHours1` | `UDINT` | |
| Output | `udiCountFb1` | `UDINT` | |
| Output | `udiOperatingHours2` | `UDINT` | |
| Output | `udiCountFb2` | `UDINT` | |
| Output | `xAlarm` | `BOOL` | |
| Output | `xAuto` | `BOOL` | |
| Input Const | `udiMinTime_V1_To_V2` | `UDINT` | 10 |
| Input Const | `udiDelay_V2_V1` | `UDINT` | 6 |
| Input Const | `udiDelay_V1_V2` | `UDINT` | 1 |
| Input Const | `udiPFbControlTime` | `UDINT` | 60 |
| Input Const | `xPFbControl` | `BOOL` | TRUE |
| Input Const | `xAlarmControl` | `BOOL` | TRUE |
| Input Const | `udiFbControlTime` | `UDINT` | 60 |
| Input Const | `xFbControl` | `BOOL` | TRUE |
| Input Const | `xForceOption` | `BOOL` | FALSE |
| Input Const | `eManModeB2` | eMANBIN | eMANBIN.Auto |
| Input Const | `eManModeB1` | eMANBIN | eMANBIN.Auto |
Methods:
> mQuit
> mResetOperatingHours
Structure:
* mQuit (Method)
* mResetOperatingHours (Method)
---
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