LVDT Measurement (Module L*)68C3 Operations Manual North Atlantic Industries, Inc. 12/19/2014Rev: 2014-12-19-0947 www.naii.com Page 210 of 330Various LVDT Configurations2-wire LVDT Connections:Connect A–B LVDT output to Signal A and the Excitation to Signal B inputs. Excitation should also be connectedto the Excitation input to enable card to sense and report any excitation loss.3/4-wire LVDT Connections:Connect A and B LVDT outputs to Signal A and B inputs. Excitation is not used, but should be connected toenable card to sense and report any excitation loss.Position DataData Hi Type: 16-bit two’s complementData Hi & Lo Type: 24-bit two’s complementRange: 0 to FFFFRead/Write: RRead Position Data: Reads the Position Data Register corresponding to a given channel.Data Format (2-wire): The output data is A / B and represents %FS. Format is two's complement. Max. positiveexcursion is 7FFF, 0 = 0, and max. negative excursion is 8000.Data format (3/4-wire): The output data is (A-B) / (A+B) and represents %FS. Format is two's complement. Max.positive excursion is 7FFF, 0 = 0, and max. negative excursion is 8000.5.0 V0.0 V10.0 VPOSITIONVa-FS OVb+FS(USUAL LVDT CONFIGURATION)(IN-PHASE)Va+Vb=10V Va+Vb=10V Va+Vb=10VVa-Vb=-10V Va-Vb=0V Va-Vb=10VVa=0V Va=5V Va=10VVb=10V Vb=5V Vb=0VExample uses10Vrms outputOPTIONALON BOARDEXCITATIONA HIA LOB HIB LOExcitation Ref Hi(Monitoring)Excitation Ref LoExcitation INPOS = a - ba + b4 WireabOPTIONALON BOARDEXCITATIONA HIA LOB HIB LOExcitation Ref Hi(Monitoring)Excitation Ref LoExcitation INPOS = a - ba + b3 WireabOPTIONALON BOARDEXCITATIONA HIA LOB HIB LOExcitation Ref Hi(Monitoring)Excitation Ref LoExcitation INa-bPOS = a - bExcit.2 Wireab
