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How to interface 3DM-GX1 using RS-485 (PXI-8431)?

I downloaded the device driver for MicroStrain's 3DM-GX1 Inertial Measurement Unit provided by NI which uses the serial RS232 protocol and its all working fine using the serial port. Here's the link http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=535813019B5F4C06E0440003BA7CCD... Now, I want to connect two 3DM-GX1 IMUs through PXI-8431 which uses the RS485 standard. Thankfully, 3DM-GX1 supports the RS485 standard but I am at my wits end on how to modify the RS232 based device driver so that the IMU functions in the RS485 mode. Any hint, help, example on the topic will be greatly appreciated.
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For the most part the primary difference between using the VISA serial drivers for RS232 and RS485 is in the actual hardware connections. The wiring between RS232 devices is different from that of RS485. There is the issue of "addressing" the units (485 allows more than one unit on the "bus" with the protocol sending an address before the actual data). Do you have the correct cables between the 485 interfaces? Also do a search for 485 protocol on this forum or on the general NI one. There is also an example in the LabVIEW help pull down NI RS-485 Transceiver Control, search on "serial"

Putnam
Certified LabVIEW Developer

Senior Test Engineer North Shore Technology, Inc.
Currently using LV 2012-LabVIEW 2018, RT8.5


LabVIEW Champion



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The cable that I am using on the PXI-8431/4 side is the standard NI RS-485/422 1meter long cable. I guess the problem lies on the other end. Microstrain's 3DM-GX1 IMU comes with a very typical connector and the cable (included in the package) connects directly to the RS-232 port on the PC. RS-232 cable can't be directly connected to a RS-485 cable, isn't it?
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I have figured out a few things that I feel I should list out: 1. The default cable coming with Microstrain's IMU is RS-232 compatible only. It cannot be directly plugged-in to a RS-485 port. 2. The EEPROM (address 46 should be set to 0) present inside the IMU needs to be programmed for the device to enter the RS-485 mode. 3. The IMU has a total set of 29 commands but the RS-485 mode puts an addressing limitation and only first 15 can be used. Looking at all this, its best that I use an RS-232 to RS-485 (and vice-versa) converter to talk to the IMU through NI PXI-8431/4. Any suggestions regarding the converter?
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Another query, I am new to this forum and I am not able to do proper formatting of my posts. Any help shall be gladly accepted. 🙂
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