Communications Manual Rev 3.10 Software Versions 3.xx
Page 8
003R-618-310
Ring Networks: Multiple Instruments to PC (RXD, TXD, GND)
Instruments with K302 software revision V3.82+ can be configured in a Ring
Network. This also requires an enhancement in the PC’s software.
The Short Ring Network layout can be used in situations up to a total cable run
length of about 150 m (500 ft) at 9600 baud in a clean EMC environment. If
there are communications errors, or for longer cable runs, lower the baud rate
to 4800 or 2400, and/or use the Long Ring Network in Figure 5 below, which
uses a separate return path from the ‘Last Instrument’ to the PC.
For DB25 connections at the PC connector, refer to Figure 3 above.
When operating in a Ring Network, the Instruments must have:
• same serial port options, i.e., baud, parity, data bits, stop bits;
• unique addresses.
Short Ring Network: Multiple Instruments to PC (RXD, TXD, GND)
Figure 4: RS-232 Short Cable Runs: Ring Network using COM Port (DB9)