- The CCM RS-232C connector is a standard 25 pin D shell connector with pins.
- The RS-232C cable must be shielded.
- When the CCM is connected to other DTE devices a Null Modem cable or an adapter is required. A personal computer is an example of a DTE device.
- When the CCM is connected to Data Communication Equipment (DCE) a Null Modem cable or an adapter is not required. Modems, printers, and terminals are examples of DCE devices.
- The DCD pin on the CCM must be asserted in order to allow the CCM to communicate. If the DCD pin is deasserted, the CCM will shut down all outgoing information.
A 25 to 25 pin cable and a null modem adapter are needed if the CCM is directly connected to a PC with a 25 pin RS-232C connector. Refer to Illustration 1.
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| Illustration 1 | g00670863 |
CCM Cable requirements for Direct Connection to PC with 25 Pin Connector (1) PC with 25 pin RS-232C connector (2) 25 to 25 pin female to male cable (3) Null modem adapter (4) CCM with 25 pin RS-232C connector | |
If the PC has a 9 pin RS-232C connector a 9 to 25 pin cable with a null modem adapter is required. Refer to Illustration 2.
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| Illustration 2 | g00670882 |
CCM Cable Requirements for Direct Connection to PC with 9-Pin Connector (1) PC with 9 pin RS-232C connector (2) 9 to 25 pin cable (3) Null modem adapter (4) CCM with 25 pin RS-232C connector | |
The null modem adapter connects the Data Transmit of one device to the Data Receive of the other device. The Null Modem adapter connects the Data Carrier Detect and the Data Terminal Ready pins in a similar manner. Cables are available from most personal computer suppliers.
Note: Verify that the cables and null modem adapters are compatible with the specifications in Tables 1 and 2.
| 25 PIN RS-232C PIN DEFINITIONS | |
| Pin Number | Description |
| 2 | Data Transmit (TX) |
| 3 | Data Receive (RX) |
| 7 | Ground |
| 8 | Data Carrier Detect (DCD) |
| 20 | Data Terminal Ready (DTR) |
| 9 PIN RS-232C PIN DEFINITIONS | |
| Pin Number | Description |
| 1 | Data Carrier Detect (DCD) |
| 2 | Data Receive (RX |
| 3 | Data Transmit (TX) |
| 4 | Data Terminal Ready (DTR) |
| 5 | Ground |
A 25 to 25 pin cable or a 9 to 25 pin cable is needed when the CCM is used with a modem. Refer to Illustrations 3 and 4. The type of cable will depend on the number of pins on the RS-232C connector of the PC.
Note: Do not use a null modem adapter to connect a modem to the PC or the CCM.
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| Illustration 3 | g00645279 |
CCM Cable Requirements for Modem Connection to PC with 9-Pin Connector (1) PC with 9 pin RS-232C connector (2) 9 to 25 pin cable (3) Modems that are connected by telephone lines (4) 25 to 25 pin cable (5) CCM with 25 pin RS-232C connector (6) Telephone line | |
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| Illustration 4 | g00645341 |
CCM Cable Requirements for Modem Connection to PC with 25-Pin Connector (1) PC with 25 pin RS-232C connector (2) 25 to 25 pin cable (3) Modems that are connected by telephone lines (4) 25 to 25 pin cable (5) CCM with 25 pin RS-232C connector (6) Telephone line | |