Sự cố thường gặp với RS-232 và RS-485 Savant

Troubleshooting Serial (RS-232/422/485) Ports

  1. Following the diagram below, jump/short the appropriate connections to create a loopback tester.


  • The color of the wire does not matter, as long as the correct pins are linked together.

  • This pinout can be applied to a female-female inline coupler or Keystone jack to test cable runs.

  1. Remove the Cat5/5e/6 cable connected to the controller's serial port (the port connected to the device having issues) at the controller end, and replace with the Loopback Tester.

  2. Open System Monitor and select the Component Status tab.

  3. Select the relevant component device and click Launch Terminal to open rpmTerminal monitoring communication to the device.

  4. Type any string of text into the command prompt and click Submit to send. If the input text is echoed back in rpmTerminal, the RJ-45 port of the controller is confirmed to work properly (See Image Below)

  5. Reconnect the cable run at the controller end, but attach the device end of the cable to the Loopback Tester instead of the component; using an inline coupler (or by shorting the relevant Transmit and Receive pins on the DB9 connection at the end of the run).

  6. Repeat steps 2-4. If the text is still echoed back successfully, the cabling to the device is functional. This indicates a potential Profile mismatch, or a problem with the component device itself.

In the event that the loopback test is successful, but communication with the third party device requires further troubleshooting, investigate the following:

  • Racepoint BluePrint configuration for incorrect/out-of-date profiles

  • Cable connections from the Savant Controller to the device (steps 6 and 7 above)

  • Serial port of affected device

Adapter Troubleshooting

While using RS232 communication within a Savant system, many issues encountered by installers are related to the colored RJ45 to DB9 adapters. The following section details the RS232 adapter troubleshooting process. Start by hooking up the adapter color called for in the device's profile in Blueprint, (example presented below), and a known working straight-through CAT5/5e/6 cable.

  • Open RacePoint Blueprint,

  • Double-click the RS-232 controlled device to open in Inspector,

  • Under the Show dropdown menu, select Control Ports,

  • Select the appropriate serial control port (RS-232C in this example),

  • Check the Adapter Color field toward the bottom of the connector info.

  1. Connect to the host in System Monitor, and select the Component Status tab. Highlight the component having the issue, and click Launch Terminal.

  2. Make a note of an RS232 command code or two from the manufacturer's protocol documentation. In the right part of the RPMTerminal window, change AVC Communications Mode to Locked. Change the mode at the top of the window to either ASCII or HEX, based on the type of command provided by the manufacturer. If you are unsure, select ASCII.

  3. Type the command exactly as it appears in the control document into the text box at the bottom of the window, and click Submit. If at any point in this process you see what seems to be valid feedback, stop. Your device should be communicating. Note that in hex mode, \h0A and \h0D are not usually valid feedback.

  4. Swap out the RS232 adapter for one of the same color, ideally a known working one.

  5. Type the command into rpmTerminal and hit submit.

  6. Swap out the RS232 adapter for one of a DIFFERENT color.

  7. Type the command into RPMTerminal and hit submit.

  8. Repeat from step 4 until you run out of adapter colors to switch to.

Trial-and-error testing with different adapter types can be useful, as manufacturers may implement firmware or board changes that affect serial communication pinout at any time without notice to Savant, and such changes could necessitate the use of a different adapter type.

If after following this process there is no valid communication displayed in rpmTerminal, the baud rate and communication settings in Blueprint may need to be adjusted. More likely, the device itself is not set up for RS232 communication. To adjust this, consult the manufacturer's current documentation.

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