Siemens SINUMERIK 840D Description Of Functions

Also see for SINUMERIK 840D: Function manual Function manual Function manual Equipment manual Programming manual

3 Safety-Related Functions 11.033.5 Safely-reduced speed (SG)© Siemens AG 2003 All Rights Reserved3-106 SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03Table3-34 Entering gear ratios into machine dataStage 840D 611 digitalMD No. Value MD No. ValueDenominator 1 36921[0] 1 1321.0 250of 2 36921[1] 1 1321.1 400gearbox 3 36921[2] 1 1321.2 625encoder/load 4 36921[3] 1 1321.3 1000Numerator 1 36922[0] 1 1322.0 1000of 2 36922[1] 1 1322.1 1000gearbox 3 36922[2] 1 1322.2 1000encoder/load 4 36922[3] 1 1322.3 1000NoteFor SE/SN, the gear stage must also be changed-over on the NCK side. Inthis case, the gear must be changed-over at zero speed or the actual valuesynchronization function used.NoteIn the circuit above (Fig. 3-13), the request signals E1/E2 for gear change forthe PLC and drive are supplied from the gear signal.For SE/SN, the gear stage must also be changed-over on the NCK side.Because only the pulses of the motor measuring system - and not those ofthe direct measuring system - are counted during motion of a motor whiledecoupled, this may result in an offset of the SI actual values. As this cannotbe avoided, gear stage changeover without errors is only possible under thefollowing conditions:1. The gear stage is selected at zero speed, the time delay does not causean offset of the two SI values.The gear stage is selected when the motor is moving (e.g. oscillating), i.e. themotor is moving although this cannot be detected at the direct measuringsystem. In this case, the following measures can be performed to avoiderrors.a) MD 36942/or MD 1342 SAFE_POS_TOL must be parameterized asnecessary and re-synchronization of the spindle (.DBX 16.6 or DBX16.7: active measuring system) must be triggered after gear changeover (ifthis has not already been done) to re-align the SI actual valuesb) The actual value synchronization function must be usedExample 2: Spindle with a 1-encoder system• The gear stage is selected from an NC program with an H function via thePLC user program.• Gear ratios are selected through 2 channels.• The encoder system is connected to the "direct measuring system" inputon the 611 digital closed-loop control module.• The machine data for the "input assignment gear ratio selection (bits 0,1, 2)" for the NCK are described inChapter 4, "Machine data for SINUMERIK 840D".Assumptions forexample 2