Parker HannifinRS-232/RS-485 Communication ProblemsIf you cannot establish serial communication with the ACR90x0 controller,use the information and procedures in this section to help isolate and resolveproblems. For more information, see “COM1 Connector” on pages 54 and 55and “COM1 Connection” on pages 72 through 75.COM1 Port Settings (RS-232 and RS-485)The COM1 port supports the following characteristics for RS-232 andRS-485 transmission:• 1200, 2400, 4800, 9600, 19200, 38400 baud (The controllerautomatically detects baud upon start-up.)• 8 data bits• 1 stop bit• No parity• Xon/Xoff flow controlPhysical SettingsVerify the physical settings for the COM1 port by following the steps in thissection.1. Use the connector pinout in Table 60 to confirm that your cable andmating connector are configured accurately for the COM1 port.Signal Pin Signal PinRX485− 1 No connect 6RX232/RX485+ 2 Mode 0 7TX232/TX485− 3 No connect 8TX485+ 4 Mode 1 9GND 5Table 60 COM1 Connector Pinout2. Confirm that mode pins 7 and 9 are assigned as indicated in Table 61for proper RS-232 or RS-485 full-duplex operation.COM1 Connector PinInterfacePin 9 (Mode1) Pin 7 (Mode 0)RS-232 Open OpenReserved Open GNDReserved GND OpenRS-485 full-duplex GND GNDNote: The controller defaults to RS-232 operation⎯pins 7 and 9 set toOpen.Table 61 COM1 Transmission ModesChapter 4 Troubleshooting 101www.comoso.com
