Pinouts - DTP12, DTP32, DTP36, DTP51
As seen from the side... pinouts of RS232 port are as follows:
| Circuit # | Function | Description |
|---|---|---|
| 1 | SLC | Serial Clock |
| 2 | TXD | Transmitted Data |
| 3 | RXD | Received Data |
| 4 | DTR | Handshake Out (Data Terminal Ready) |
| 5 | CTS | Handshake In (Clear to Send) |
| 6 | V+R | V+ 5V regulated (from Keyboard Interface) |
| 7 | V+U | V+ 12V unregulated (from AC adaptor) |
| 8 | PGD | Power Ground |
| 9 | DGD | Digital (signal) Ground |
| 10 | SD | Serial Data (part of Keyboard Clock line) |
Pin #1 is leftmost when unit is sitting upright.
Those interested in making their own interface cables - read on!
The schematics below are useful when attaching the instrument directly to the computer. Each of the following varients uses only the 'A' lines of the instrument. 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.
For the Macintosh world the following interface represents a full, bi-directional solution complete with two-way handshaking:
| 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.
