Lake Shore Model 421 Gaussmeter User’s Manual6-6 Service6.5.1 Serial Interface Cable WiringThe following are suggested cable wiring diagrams for connecting the Model 421 Serial Interface tovarious Customer Personal Computers (PCs).Model 421 to PC Serial Interface – PC with DE-9PModel 421 DE-9P Standard Null-Modem Cable (DE-9S to DE-9S) PC DE-9P5 - GND 5 - GND2 - RD (in) 3 - TD (out)3 - TD (out) 2 - RD (in)4 - DTR (out) 6 - DSR (in)6 - DSR (in) 4 - DTR (out)1 - NC 7 - RTS (out)7 - DTR (tied to 4) 8 - CTS (in)8 - NC 1 - DCD (in)Model 421 to PC Serial Interface – PC with DE-25PModel 421 DE-9P Standard Null-Modem Cable (DE-9S to DB-25S) PC DB-25P5 - GND 7 - GND2 - RD (in) 2 - TD (out)3 - TD (out) 3 - RD (in)1 - NC 4 - RTS (out)7 - DTR (tied to 4) 5 - CTS (in)8 - NC 8 - DCD (in)6 - DSR (in) 20 - DTR (out)4 - DTR (out) 6 - DSR (in)Model 421 to PC Interface using Null Modem AdapterModel 421 DE-9P Null Modem Adapter PC DE-9P5 - GND 5 - GND2 - RD (in) 3 - TD (out)3 - TD (out) 2 - RD (in)1 - NC 4 - DTR (out)6 - DSR (in) 1 - DCD (in)4 - DTR (out) 6 - DSR (in)7 - DTR (tied to 4) 8 - CTS (in)8 - NC 7 - RTS (out)9 - NC 9 - NCNOTE: Same as null modem cable design except PC CTS is provided from theModel 421 on DTR.
