The HEAD2 device manages the control of heads for sanders, grinders and milling machines working material flowing along a conveyor belt. You can simultaneously handle up to 8 heads, individually configurable working, using various setup parameters.
An important feature is the ability to set of fixes related to the operation of the heads, in order to compensate for any delays to answer machine. These corrections are calculated taking into account the speed of the belt.

In the configuration unit, the INTDEVICE section must be declared so that you have the hardware resources necessary for the use of the HEAD2 device. Must be add the following definition:

;---------------------------------
; Internal device declaration
;---------------------------------
INTDEVICE
<device_name> HEAD2 TCamp ICont inp01 inp02 inp03 out1 out2 out3 out4 out5 out6 out7 out8

where:

	ATTENTION: It is necessary that each definition are present on the same line. In case you do not want to assign a resource, for example inp02, you must enter in the appropriate field the string X.X.

The HEAD2 device allows you to simultaneously handle up to 8 working heads, that can be individually configured, using the setup parameters, how planing, milling or grinding machines. The device allows you to make, during processing, corrections of workloads to compensate for delays in response of the machine. These corrections will be made taking into account the tape drive speed so you can automatically compensate for workloads according to variations of the speed.
The system consists of a bi-directional transducer (typically an encoder) bound to the material on the conveyor belt and a maximum of three fixed presence sensors piece that allow acquisition and correction, for the entire length of the conveyor belt, for the image of the pieces introduced.
In the case of use of heads as edging, in the program you can set after how many meters you will have to activate the lowering of the head for wear compensation. In the case of use of heads as sanders, in the correction data you can set the delay quota descent heads early slab and the proportion of early ascent of relative to the end plate. When using milling heads, in data processing, you can set the delay to the start of the quota from the beginning milling and length of the slab milling.
The card allows maximum 30 working contemporary pieces.

By receiving impulses from a bi-directional transducer (typically an encoder mounted on the motor shaft that moves the conveyor belt) the device can calculate the speed of movement in the desired unit (properly setting measure, pulse, unitvel and decpt).
The device counts the number of pulses received over a period of time defined by the tbf parameter and then calculates the speed in that time interval. The possibility of programming this parameter allows you to have greater accuracy depending on the speed of the tape. For example, at very low speeds we can't set a sampling time too high, in this case, the device would have a hard time calculating the speed.

Configuring a head as sander, it's possible that works the material only “in the center”, by this we mean that you can delay your descent or anticipate the ascent of each individual head using the downhone and risehone parameters.
The data entered in these parameters can take positive or negative values.
In case you set positive values the piece will be work as per drawing below; the quota is equal to the value set in the downhone parameter, the b quota is equal to the value set in the risehone parameter while the c quota is the space in which the head works effectively.

In case you set negative values the piece will be work as per drawing below; the a quota is equal to the value set in the downhone parameter, the b quota is equal to the value set in the risehone parameter.

When using a head as miller you may decide to work for a given length (lengthmill) at some distance from the beginning or the end of the piece.
To run the cable working with respect to the beginning of the piece, you should set the parameter risemill = -1 and the piece will be worked as per drawing below; the a quota is equal to the value set in the downmill parameter, while the b quota is equal to the value set in the lengthmill parameter.

To run the cable working with respect to the end of the workpiece, you must set the parameter downmill = -1 and the piece will be worked as per drawing below; the c quota is equal to the value set in the risemill parameter, while the d quota is equal to the value set in the lengthmill parameter.

In the case of use of heads as sander or milling machine, You can anticipate the descent or ascent of each individual head depending on the speed of the conveyor belt using the downlag1,2,3 and riseadv1,2,3 parameters. The data entered in these parameters can take positive or negative values. In case you set positive values and the ribbon is advancing at the speed set, in corrvel1,2,3 the piece will be worked as per drawing below; the a quota is equal to the value set in the downlag1,2,3 parameter while the b quota is equal to the value set in the riseadv1,2,3 parameter.

In the case where negative values are set the piece will be worked as per drawing below; the a quota is equal to the value set in the downlag1,2,3, parameter while the b quota is equal to the value set in the riseadv1,2,3 parameter.

There are also two parameters (actriseadv and actdownlag) that lets you know the current correction value applied to a given head.

It is made so you can create a feature lead and lag correction depending on the speed of the tape. Were determined three linearization points (corrvel1, corrvel2 and corrvel3), each of these corresponds a clear lead and lag correction (riseadv1,2,3 and downlag1,2,3). For the speed of the tape contained within the linearization points, is treated as correction value, the straight line joining the two end points of linearization. An example is shown in the following figure.

The feature will go always to the origin except in cases where corrvel1 is set equal to 0: in this case, the downlag1 value (or riseadv1) will be to consider how to fix at zero speed (that is an offset). An example is shown in picture.

Suppose that while working a piece broke, you must lock the machine to remove the piece from tape.
To restart the machine, the heads about that piece will continue to fall, creating serious problems to the functionality of the machine.
To work around this problem, You can delete a single item from the chain of working, using the CLPIECE command.

In case the machine to be programmed to have a particular configuration, you can use more than one device. Declaring two devices, with the same address for input piece detection and with distance sensor-heads properly configured, you can manage a machine which has more than eight heads.
If you declare two devices with different sensors for detecting piece, they can manage a machine with two parallel production lines.

Lists some notes on operation of the device:

• the correction value for offsetI01 is calculated every 250 ms, correction values for heads are calculated every 2 s,
• the device does not support the operation with a “infinity piece”: the REGOFF command leave the control outputs to QCL, which can develop these and other features,
• because of the different ways to reset (see the resettype parameter), the list of parameters that are saved with the SaveData command is much greater than just the retentive device parameters.

All commands (generic, memory and tape programs) are in order of priority, independently of the table on which were placed.