A workpiece clamping table of a woodworking machine with vacuum chucks arranged on clamping bridges for the force-locked clamping of workpieces by means of negative pressure, wherein the individual vacuum chuck, in order to set up the workpiece clamping table, can be manually placed on a clamping bridge in a position optically marked by at least one luminous emitting light source of a light strip, characterised in that - the individual clamping bridge along its usable length comprises, apart from the light strip comprising the individual emitting light sources, a receiver rail with a downstream light receiver, - the light receiver comprises an evaluation unit or an evaluation unit is arranged downstream of the light receiver, which evaluation unit converts the received signals into a sequence of useful signals with can be read by the woodworking machine, - the individual vacuum chuck comprises at least one energy source, at least one pressure sensor on the side facing the workpiece and/or at least one pressure sensor on the side facing the clamping bridge, at least one identification component and at least one computing unit for implementing a serial or parallel signal transmission for displaying the operating state by means of optical or acoustic means and/or for communicating with the machine tool, - the individual vacuum chuck and the woodworking machine each comprise at least one transmitter and at least one for the transmission of information by means of optical signals and/or by means of radio signals, - the vacuum chuck comprises at least one optical signal receiver which can recognise the optically marked position when a vacuum chuck has been placed on the clamping bridge, - the vacuum chuck comprises at least one emitting light source, the light, exit whereof facing the vacuum chuck side is arranged at a short distance from the receiver rail for the purpose of coupling the emitted light signals. - the individual clamping bridge along its usable length comprises, apart from the light strip comprising the individual emitting light sources, a receiver rail with a downstream light receiver, - the light receiver comprises an evaluation unit or an evaluation unit is arranged downstream of the light receiver, which evaluation unit converts the received signals into a sequence of useful signals with can be read by the woodworking machine, - the individual vacuum chuck comprises at least one energy source, at least one pressure sensor on the side facing the workpiece and/or at least one pressure sensor on the side facing the clamping bridge, at least one identification component and at least one computing unit for implementing a serial or parallel signal transmission for displaying the operating state by means of optical or acoustic means and/or for communicating with the machine tool, - the individual vacuum chuck and the woodworking machine each comprise at least one transmitter and at least one for the transmission of information by means of optical signals and/or by means of radio signals, - the vacuum chuck comprises at least one optical signal receiver which can recognise the optically marked position when a vacuum chuck has been placed on the clamping bridge, - the vacuum chuck comprises at least one emitting light source, the light, exit whereof facing the vacuum chuck side is arranged at a short distance from the receiver rail for the purpose of coupling the emitted light signals.