Input Description¶
MCX_CamSwitchMulti_dc provides the possibility to switch a cam on/off at projected positions. The position is given by an encoder, which must be available, if the cam switch functionality is to be used.
The switch-on-position and the on-range are individually changeable online. Further more a different compensation time in both directions can be added to the switch position.
The compensation time makes the switch a “dynamic” switch. The position where to switch on and off is calculated according to the actual velocity, in a way that the output occurs a certain time before (negative compensation) or after (positive compensation) the position has been reached. The time is given at the input compensation, the distance is calculated. The accuracy of time to be reached depends on the stability of velocity, which means just on a constant velocity, the time will be correct.
OnDistance = velocity * OnCompensation;
OffDistance = velocity * OffCompensation;
The switch will be switched on at “FirstOnPosition + OnDistance” and switched off at “FirstOffPosition + OnRange + OffDistance”. While switched on, no new calculation of distance will be done.
CamSwitchMulti matches the CamSwitchComfort with an additional information about revolutions. It might switch a cam a distance of several revolutions ahead. The OnDistance and OffDistance might as well cover a distance of several revolutions. OnRange must not be larger then 1 revolution. With revolutions=0, the behaviour will be the same as MCX_CamSwitchComfort_dc.
“Revolutions” inside the device start from counting up 0 at power on, therefore, even with a single-turn encoder, the “multi” could be used. The revolutions do not match the revolutions counting of a connected multi-turn encoder, it has just a relative value.
Connected with a “…shift”, (BinaryShift or CamShift) it will trigger a cam several revolutions ahead.
On different values for OnCompensation and OffCompensation, the time to be switched on will be increased or decreased. For example, with OnCompensation >0 and OffCompensation <0, the Cam will be switched on later and switched off earlier, so the angle to be switched on is decreased. The minimum time will be a single device cycle (200 µs), the maximum will be a number of revolutions according to the input “revolution+1”, with a single cycle off.
The actual state of the cam can also be monitored with the output “state”.
Enable
| Data_Type | Default_Value | Range | Unit |
|---|---|---|---|
| BOOL | - | - | - |
The Function Block is activated with Enable TRUE. With Enable=FALSE, the respective cam will be switched off immediately.
FirstOnPosition
| Data_Type | Default_Value | Range | Unit |
|---|---|---|---|
| WORD | - | - | - |
The value of FirstOnPosition is automatically truncated to the resolution of the circle without notice. For example, all FirstOnPosition greater than 36000 will be limited to 36000 (given if the default resolution of CI51x-ETHCAT cam is used).
FirstOnPosition can be changed at any time. It will be immediately valid after sending to the CI51x-ETHCAT via the POU.
OnCompensation
| Data_Type | Default_Value | Range | Unit |
|---|---|---|---|
| DINT | - | - | µs |
The switch action is rescheduled with Compensation:
- If Compensation is positive, the switch action will be delayed by the value of Compensation.
- If Compensation is negative, the switch action will be brought forward by the value of Compensation.
OnRange
| Data_Type | Default_Value | Range | Unit |
|---|---|---|---|
| WORD | - | - | - |
The value of OnRange is automatically truncated to the resolution of the circle without notice. For example, all OnRange greater than 36000 will be limited to 36000 (given if the default resolution of CI51x-ETHCAT cam is used).
OnRange can be changed at any time. It will be immediately valid after sending to the CI51x-ETHCAT via the POU.
OffCompensation
| Data_Type | Default_Value | Range | Unit |
|---|---|---|---|
| DINT | - | - | µs |
The switch action is rescheduled with OffCompensation:
- If OffCompensation is positive, the switch action will be delayed by the value of OffCompensation.
- If OffCompensation is negative, the switch action will be brought forward by the value of OffCompensation.
CamNumber
| Data_Type | Default_Value | Range | Unit |
|---|---|---|---|
| WORD | - | 1…32 | - |
Number of the cam: this number runs from 1..32. The parameter cam_To_Track[0..31] must be used to map the cam to the available digital outputs. A configuration tool must be used for setting the cam_To_Track.
csdc
Data type: CSDCX_REF_TYPE
The 2 elements in_csdc and out_csdc of csdc must be initialized with the beginning address of the input data area and the output data area to facilitate proper function of the cam.