circuit 74 is connected in a manner shown in greater detail in fig5 via lines 76 77 78 and 79 to the respective measuring head 15 or 25 to the respective control poles 42 43 or 52 53 and to a level control circuit 86 and a comparator circuit 73 which are for example accommodated in a cabinet next to the machine the circuit board 72 also carries a plug in bushing 81 into which the cable 11 for example for both selection magnet systems leading to the pattern apparatus and to the circuits 73 86 can be plugged the hollow space 71 is covered by a detachably secured cap 82 the substantially approximately rectangular housing 66 has cooling fins 83 on its long sides the housing 66 is secured via connecting screws that are inserted into bores 84 to the front panel 13 of the cam carriage 12 such that it is detachable from outside so that it is replaceable on its own as a component containing the selection magnet systems without requiring further assembly or disassembly from fig5 the circuit layout of the control magnet assembly 10 according to the invention having the electrical circuits 73 74 86 can be seen each pair of control coils 42 and 52 or 43 and 53 is connected in parallel with one another and near the trigger circuit 86 which is supplied with direct current u m of 40 v for example is connected to the pattern apparatus not shown of the knitting machine for the pattern dependent triggering via a line 87 connected to the trigger circuit 86 is.