Circuit # | Function |
1 | Generally Not Used (+5v @ 50 ma) |
2 | Transmit Line |
3 | Receive Line |
4 | DTR (Data Terminal Ready) |
5 | CTS (Clear to Send) |
6 | Not Used |
7 | +12v (Used if charged via cable) |
8 | Charger Ground |
9 | Digital Ground |
10 | Generally Not Used (-5v @ 50 ma) |
A minimum wiring for 'send only' communication (IBM) is as follows:
X-Rite (10c/RJ45) | IBM 9Pin (DB9p) | IBM 25Pin (DB25p) |
2 X'mit data | 2 Rec'd data | 3 Rec'd data |
9 Digi Ground | 5 Digi ground | 7 Digi ground |
Many devices will require some kind of hardwire handshaking. All instruments provide a +8 volt signal on line 4 ( our DTR ) which can be connected to the receiver's hardwire handshake line ( usually CTS ). Our DTR is dropped during power-up and while taking measurements to inform the receiver that we are not ready to accept data. Similarly each unit can monitor its line 5 ( our CTS ) to see if the receiver is ready to accept data. Should you need the additional wiring a more complete schematic follows:
X-Rite (10c/RJ45) | IBM 9Pin (DB9p) | IBM 25Pin (DB25p) |
2 X'mit data | 2 Rec'd data | 3 Rec'd data |
4 DTR handshake | 6 DSR | 5 CTS |
5 CTS/Busy handshake | 7 RTS | 20 DTR |
9 Digi Ground | 5 Digi ground | 7 Digi ground |
If two way communication is desired then one more wire may be added; i.e.:
X-Rite (10c/RJ45) | IBM 9Pin (DB9p) | IBM 25Pin (DB25p) |
2 X'mit data | 2 Rec'd data | 3 Rec'd data |
3 Rec'd data | 3 X'mit data | 2 X'mit data |
4 DTR handshake | 6 DSR | 5 CTS |
5 CTS/Busy handshake | 7 RTS | 20 DTR |
9 Digi Ground | 5 Digi ground | 7 Digi ground |
If Pin5 is turned off (instrument I/O configuration), the instrument will not monitor the handshake line from the computer / printer / etc. With most printers this will result in data overflow. With most computers this handshake is not required.
X-Rite (10c/RJ45) | Macintosh (8pin/DIN) |
2 X'mit data | 5 RxD- Receive data (minus) |
3 Rec'd data | 3 TxD- Transmit data (minus) |
4 DTR Handshake Out | 2 HSKi/Clock Handshake In |
5 CTS Handshake In | 1 HSKo Handshake Out |
8 Charger Ground | 8 RxD+ Receive data (plus) |
9 Digi Ground | 4 Digi ground |
The above description is electrically equivalent to X-Rite's PN SE108-79 interface cable.