Oriental Motor : ARD-KD & Labview driver

[OricaSCE]

Hey Minikisscool,

Thanks for posting these files!

I'm working on a project with a AZD-KD driver from Oriental Motor and have been able to write commands but am having issues reading Modbus holding registers. Whenever I send a command to read certain registers it returns same command I sent out. I'm wondering if you still have the MB Serial Init.vi and the MB Serial Master Query (poly).vi sub VIs that are in the read register 1.2_COM.vi you posted a few years ago? They are missing from that VI you sent. I feel these could help me fill in some of the gaps I have in my code.

Thanks in advance for any help or files you can provide to help me out!

[OricaSCE]

Disregard my last message, I found that those VIs were in a were in an older Modbus library...

Even when using your program, I still am not able to read holding registers from the OM driver. The response I get back in Labview is a reflection of the query I send out. (Example: If I'm trying to read a holding register at starting address 00CC, I get back CC00. If I request 0102, I get back 0200. It doesn't matter how many registers I request, I always get back the same reflected one register response. I'm interested to hear how you wired up these components and if there was any special configuration need in the MEXE02 software from Oriental Motors.

Any assistance you can provide would be great. Thanks!

[Minikisscool]

Hi, 

For ModBus, as said, when i developped the program, i found 3 library

MODBUS Library for LabVIEW Version 1.21 (not choosed)
http://www.ni.com/example/29756/en/

LabVIEW Modbus API v1.1.3.32 (not choosed)

https://decibel.ni.com/content/docs/DOC-30140

MODBUS included in DSC module for LV2014 (choosed)
http://zone.ni.com/reference/en-XX/help/370622M-01/lvmve/choose_modbus_ioserver_vi/
http://sine.ni.co...

For connection between computer and controller, i used USB converter to RS485.
http://www.ftdichip.com/Support/Documents/DataSheets/Cables/DS_USB_RS485_CABLES.pdf

Then, i used MEXE02 to check read / write and to test specific function read register,....

I saw, i posted 2 files that wat usefull to convert data

From computer, can you read / write sucessfull registers with MEXE02 ?

[OricaSCE]

Hey,

Thanks for the clarification and recommendation for the USB to RS485 converter. So far I've been trying to get communications through a cRIO with a 9871 module and have tried using hyperterminal. No success other then sending commands so far, still unable to read data back from the driver.

I will order the converter and try to go straight from my computer.  

[Minikisscool]

When I started, i try this toolkit from saphir
http://www.saphir.fr/en/produits/gmodbus-over-serial-line-8.html

You can fin it in VIPM. It's a paid toolkit but from memory, you try during some days.

https://vipm.jki.net/

Last, Oriental Motor in my kingdom give me some program to test modus communication.
It was non official program, but they used it internal.

[Kamalkd]

 Hi,

Can you provide the labview programs that you got from your local oriental motor support.

-Kamal

[Kamalkd]

Hi,

Did you have any luck with the developing modbus vi for AZD-KD system?

-Kamal

[OricaSCE]

Hey Kamal,

The rep I spoke with at Oriental Motor wouldn't share their internal software but was happy to help with various Modbus command questions I had. I did end up building my own VI. See below of how the Modbus port is set up.. As for wiring, the RXD+ and TXD+ on the CRio get connected to the TR- on the ARD-KD and the RXD- and TXD- on the CRio get connected to the TR+ on the ARD-KD. A 120Ohm resistor was connected over the TR- and TR+ where the bridge was made. The total length of wire between the two devices was only 2-3 meters so another resistor may be needed if your ARD-KD is further away. I found that delays were needed between Modbus commands of at least 20-30ms and that the motor would not respond to getting the same command twice in a row. Hope this helps you get yours working!

-Pat

[axelmogr]

Hello Pat,

I'm also trying to interface an Oriental Motor BLDC motor (in this case through a BLVD40NM driver, same basic function as the ARD-KD) with a cRIO 9053 and I've had no success trying to interface with the motor. I built the attached VI to be able to read the holding registers but absolutely nothing happens. I am curious about the connections you mentioned in your post, however. For interfacing the motor driver with the NI 9871 module following a 2-wire half-duplex setup, you say you connected TXD+ and RXD+ on the cRIO to the TR- pin on the driver, the TXD- and RXD- to the TR+ pin and the terminating resistor bridging the two combined leads.

Was that just a typo? I did what I thought was correct by connecting TXD+ and RXD+ to TR+, TXD- and RXD- to TR-, bridging the leads with the terminating resistor and lastly connecting GND to GND. Is this incorrect?