Rockwell Automation 2708-DH5B2L_DH5B4L Attended Workstation - Manual (Page 132)

A–B
E
Appendix
E–1
Distance Limitations
Network (RS-485) Cable Length
Terminators are REQUIRED for all network cables longer than 500 feet.
For extremely long network cables, it may be necessary to turn on the
terminator switch of the very last workstation in addition to the Master.
No network may have more than 10,000 feet of cable.
If distances longer than 10,000 feet are required, or more than 32
workstations required, see Chapter 2, Complex Networks.
RS-232 (MASTER or HOST) Cable Length
The maximum length depends on baud rate and site specific conditions. It is
recommended that only high quality, shielded cable (Belden 8723) be used.
The lengths described below should be considered the safe guidelines for
layout purposes.
At 9600 baud the RS-232 cable may be 100 feet in length.
At 4800 baud the RS-232 cable may be 200 feet in length.
At 2400 baud the RS-232 cable may be 500 feet in length.
At 1200 baud the RS-232 cable may be up to 1000 feet in length.
If you are using RS-422, you can usually get substantially longer cable
lengths than those listed above. Check the information for your Host
computer or the EIA RS-422 standard for more information.