Connecting RS-422 in Party Mode

Connecting RS-422 in party mode can be fraught with issues. Following a few simple best practices can save a good deal of time troubleshooting.

Configuring the MDrive

WIth a comm converter and the MDrive units you plan to use in Party Mode at hand, perform the following:

    1. Connect in single mode RS-422 and initiate communication, download any programs if required.
    2. Assign a device name (DN="<A-Z, a-z or 0-9>") i.e DN="A".
    3. Set the party flag to 1 (PY=1).
    4. Press CTRL+J to activate party mode.
    5. Type in [Device Name]S and press CTRL+J (Saves the DN and Party Configuration) i.e. AS CTRL+J.
    6. Remove power and label the drive with the assigned DN.
    7. Repeat for each system MDrive.

Wiring communication

Use the following diagram to wire your multidrop system. Use shielded twisted pair cabling with the shield earthed at the communication converter end of the network. Recommended comm converter and cabling is the MD-CC402-001 and prototype development cable PD10-1434-FL3.

Terminiating the cable

Under 15 ft we recommend that no termination is used. Over 15' (4.5 meters) The value of capacitance should be calculated using the formula above to find the cable round trip delay divided by the characteristic impedance of the cable (Zo).