The Comtrol RocketPort is a multiport RS-232 serial adapter available in ISA, PCI, and Universal PCI form factors, providing 4 to 32 asynchronous EIA-232 ports per card. On models designated with the “4J” suffix, the ports are exposed directly as RJ45 jacks on the card edge, each carrying standard DTE signals compatible with TIA-232-F. The RocketPort range was introduced in the mid-1990s and was widely used in multi-user UNIX and Windows NT environments where a high density of RS-232 serial connections was required. Other models fan out through a 68-pin or 78-pin VHDCI D-sub connector to individual DB9 or DB25 breakout cables per port.
RJ45 FEMALE CONNECTOR at the RocketPort card)
RJ45 MALE CONNECTOR at the cables
| Pin | Name | Description | Dir |
|---|---|---|---|
| 1 | RTS | Request To Send | OUT |
| 2 | DTR | Data Terminal Ready | OUT |
| 3 | GND | Ground | OUT |
| 4 | TXD | Transmit Data | OUT |
| 5 | RXD | Receive Data | IN |
| 6 | DCD | Data Carrier Detect | IN |
| 7 | DSR | Data Set Ready | IN |
| 8 | CTS | Clear To Send | IN |
Notes
The RJ45 connector on 4J-series cards carries a standard EIA-232 DTE pinout via an RJ45-to-DB9 adapter cable; a null-modem cable is required for DTE-to-DTE connections. On fan-out cable models, the DB9 per-port pinout follows the standard EIA-232 DTE assignment (CD=1, RxD=2, TxD=3, DTR=4, GND=5, DSR=6, RTS=7, CTS=8, RI=9) and the DB25 per-port pinout uses the standard DB25 RS-232 assignments (TxD=2, RxD=3, RTS=4, CTS=5, DSR=6, GND=7, DCD=8, DTR=20, RI=22). Ground must be tied to signal ground in quad and octacable fan-out configurations.
Signals
- RTS — Request To Send; output from the DTE (host) asserting readiness to transmit to the connected DCE
- DTR — Data Terminal Ready; output from the DTE indicating the host is active and ready for communication
- GND — Signal ground; common reference for all EIA-232 signal levels on this port
- TXD — Transmit Data; serial data output from the DTE to the connected DCE
- RXD — Receive Data; serial data input to the DTE from the connected DCE
- DCD — Data Carrier Detect; input to the DTE indicating the DCE has detected a carrier signal
- DSR — Data Set Ready; input to the DTE indicating the connected DCE is powered and ready
- CTS — Clear To Send; input to the DTE from the DCE granting permission to transmit