Axis Cassettes

Type

Field of applications / Features

The purpose of the axis cassette is to simplify the wiring (encoder/switch cabinet) and to increase its immunity of interference. If the electronic components of the axis cassette were housed inside the encoder, the entire wiring would have to be routed over long distances to parts of the machine with difficult access, and screened cables and sealed plugs would have to be used. This would be complicated and expensive in the case of many parallel outputs. With an axis cassette, all you have to do is to insert the screened serial encoder connection into the machine. This connection requires a maximum of 6 cores twisted in pairs and is highly immune to interferences due to the use of a checksum or galvanic isolation. The rest of the wiring is housed in the protected switch cabinet with single cores and terminal strips. If longer wires are used, it is advisable to screen them.

Since the equipment of the axis cassettes varies according to the customer's specifications, different programming parameters are also necessary. For this purpose, the hardware equipment features are programmed into the axis cassettes at the factory; consequently, only those parameters required for the available hardware appear when programming the PC.

You find operating manuals of various customized axis cassettes on Documentations/Downloads - Technical - Operating manuals/Assembly instructions - Application modules.

Functional description

The axis cassette reads the actual values from an encoder via a specially stored synchronous/serial transmission protocol and manages the received information itself according to the set direction of rotation and scaling. Due to the evaluation of a checksum generated by the SSI transmission protocol, the subsequent switching-on unit is able to provide the "filtered" positioning value. In single evaluations of the SSI protocol, this particular method shows far less susceptibility to errors. This alternative has proven especially useful in the case of EMC problems, as the "intelligence" has been relocated to the cassette, which is usually installed in a switch cabinet. Depending on the design of the cassette, actual values as well as cams can be output via different interfaces, so that their adaptation to all common control systems is guaranteed. Monitoring functions implemented in the cassette can be enabled via programming and output in addition to the useful data. The programming of the encoder parameters and cam functions etc. is performed via a PC program. This program is structured to allow easy operation of the cassette and thus ensures that the application remains clear and simple. In addition, the program can be used to store all system settings and to help print out parameter settings.