Control with MODBUS RTU throwing errors

[Chompy80]

Hi,

I’m using the OpenRB-150 and XL330-M288-T as suggested in the XL330 version of your gripper. the control with lite 6 python code works to open and close the gripper, but "control_openRB150_with_modbus_rtu" python script throws errors. I have the robot's baud rate set to 115200, however I’m getting the following error:

$ python3 control_openRB150_with_modbus_rtu.py 10.10.0.182 coco
SDK_VERSION: 1.11.6
ROBOT_IP: 10.10.0.182, VERSION: v2.4.113, PROTOCOL: V1, DETAIL: 6,9,LI1006,DL1000,v2.4.113, TYPE1300: [0, 0]
change prot_flag to 3
[set_state], xArm is ready to move
set_tgpio_modbus_baudrate, code=0
[SDK][ERROR][2024-09-07 21:24:54][base.py:348] - - API -> getset_tgpio_modbus_data -> code=1, response=[]
[SDK][ERROR][2024-09-07 21:24:56][base.py:348] - - API -> getset_tgpio_modbus_data -> code=1, response=[]
[SDK][ERROR][2024-09-07 21:24:58][base.py:348] - - API -> getset_tgpio_modbus_data -> code=1, response=[]
[SDK][ERROR][2024-09-07 21:25:00][base.py:348] - - API -> getset_tgpio_modbus_data -> code=1, response=[]

[hygradme]

Do you cross the TX and RX lines as described in the instruction?
https://github.com/hygradme/OpenParallelGripper/blob/XL330_version/XL330_version/electronics/grove_cross_cable.jpg
I also encountered same errors several times and usually it seems to be caused by wiring issues.

[Chompy80]

Thank you for your reply. I did swap the TX & RX wires as described. I will go through all the instructions again to ensure everything else is wired properly. For now, I’m able to control the gripper via analog signaling via the Lite 6.

Thank you so much for creating this repo. I greatly appreciate you doing so, as I am now able to create grippers that don't rely on a vacuum pump!

[carltech22]

Hello,
Did you ever figure out the issue on the ufactory UI when sending modbusRTU data from the OpenRB-150?
I am having the same issue and I'm wondering if there is anything I am missing.

[hygradme]

@carltech22
What kind of data did you send from OpenRB-150?

[hygradme]

I updated
OpenRB_modbusRTU.ino and control_openRB150_with_modbus_rtu.py
so that the host machine can receive the feedback of actual position of the gripper using Modbus-RTU.

Ideally, using Read Input Registers(0x04) function code looks suitable for this case to prevent the host machine from accidentally overwriting the gripper's actual position. However, xArm API(getset_tgpio_modbus_data) does not appear to support 0x04, so you have to use Read Holding Registers(0x03) instead to read data from the gripper.

659f8fa