Installing the HP AdvanceStack Internet Router
Preparing to Connect to a Network
Signaling Standards SupportedThe synchronous serial port supports the following signaling standards: EIA/ TIA-232, EIA/TIA-449, V.35, X.21, and EIA-530. You can order a DB-60 shielded serial transition cable from HP that has the appropriate connector for the standard you specify. The router end of the shielded serial transition cable has
aDB-60 connector, which connects to the DB-60 port on the rear panel of the router. The other end of the serial transition cable is available with the connector appropriate for the standard you specify. The documentation for the device you want to connect should indicate the standard used for that device. The synchronous serial port can be configured as DTE or DCE (except EIA-530, which is DTE only), depending on the attached cable. To order a shielded serial transition cable, refer to the section “Ordering Information” in chapter 1 “HP AdvanceStack Internet Router Overview” and appendix A, “Cable Specifications”.
N O T E | All serial ports configured as DTE require external clocking from a CSU/DSU |
| or other DCE device. |
| Although attempting to manufacture your own serial cables is not recom- |
| mended (because of the small size of the pins on the DB-60 serial connector), |
| cable pinouts are provided in appendix A, “Cable Specifications”. |
| |
Distance LimitationsSerial signals can travel a limited distance at any given bit rate; generally, the slower the data rate, the greater the distance. All serial signals are subject to distance limits, beyond which a signal degrades significantly or is completely lost.
Table 2-3 lists the maximum speeds and distances for EIA/TIA-232 signals. This signalling standard supports unbalanced circuits at signal speeds up to 64 Kbps.
Table 2-3. EIA/TIA-232 Speed and Distance LimitationsData Rate (Baud) | Distance (Feet) | Distance (Meters) |
2400 | 200 | 60 |
4800 | 100 | 30 |
9600 | 50 | 15 |
19200 | 50 | 15 |
38400 | 50 | 15 |
64000 | 25 | 7.6 |
| | |
