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8.To check 2-wire RS-485, you must either enable the receiver by moving the receive jumper to RX ENABLE mode (Table 1), or use one Port to transmit to another 2-wire RS-485 port or converter by cross connecting and loading COMTest twice, one copy for each port.
Characters typed in one copy of COMTest will appear in the receive window of the other. Note that software must ignore the RS-232 handshaking lines in RS-422/RS485 mode, the input lines (CTS, DSR, DCD, RI) are not pulled high.
9.Some manufacturers label their data connections for A and B reverse of the standard for RS-422 or RS-485, so that the A line is (+) and B line is inverted (-) following the IC standard. In such a case, just swap the wires and try it. No damage occurs in the RS-485 mode, just no devices will respond. The EIA standard for signal labels defines the B line as positive relative to A during the “MARK” state.
10.Try another software package for troubleshooting. Some applications try to bypass the Windows drivers and access the hardware directly.
11.Check our website for available FAQ's or troubleshooting hints.
12.Contact B&B Electronics Technical Support for troubleshooting assistance.
USA Office
Technicians are available at (815) 433-5100 to answer your questions from 8 AM - 5 PM weekdays (Central Time).
Email: <support@bb-elec.com>
European Office
Technicians are available at +353 91 792444 to answer your questions from 8:30 AM – 5 PM weekdays (GMT Time).
Email: support@bb-europe.com
50 | Chapter 7 | Documentation Number 3PCIO1-0903 Manual |
B&B Electronics Mfg Co – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph 815-433-5100 - Fax 815-433-5104 B&B Electronics Ltd – Westlink Comm. Pk. – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445