Motoman Ros I/O read/write error

[Avgrobo]

We're trying to control Festo make gripper integrated with Yaskawa GP12 robot via ROS using rosservice. On calling the service execution error states that Its illegal to write or read the address.

Kindly support on resolving the error to control.
Thanks

[gavanderhoorn]

First: please don't post screenshots of terminal output. It's all text, so please copy-paste it into a fenced code block instead.

Having written that: every robot controller supported by MotoROS1 only allows a few ranges of addresses to be written to. See the service documentation for information:

motoman/motoman_msgs/srv/WriteSingleIO.srv

Lines 2 to 15 in 70d731c

	# Write 'value' to the IO element at 'address'.
	#
	# This service does not return anything.
	#
	# Addresses are plain, base-10 integers, as used and displayed by the controller
	# (on the teach pendant for instance).
	#
	# Only the following addresses can be written to:
	#
	# - 27010 and up : Network Inputs (25010 and up on DX100 and FS100)
	# - 10010 and up : Universal/General Outputs
	#
	# Refer also the Yaskawa Motoman documentation on IO addressing and
	# configuration.

This is not a limitation of MotoROS btw, but a MotoPlus / controller limitation. Similar to how other remote control interfaces (like HSES) are limited to writes to only those ranges.

Could you describe how your gripper is connected to your controller and how it's been configured?

PS: and you most likely already know, but ROS Melodic has been EOL since June this year, so will not see any updates nor enhancements any more.

---

Edit: something else I notice in your screenshot: try to avoid octal number notation. Anything with leading zeros (0) will be interpreted as octal number notation. Not by the driver, but by the YAML parser part of rosservice call. That's likely not what you want.

[Avgrobo]

Thank you for the reply.

Referring to the above message, we tried the possible address with read and write single io service but no movement was observed from the gripper.

Attaching the screenshot of the controller output for your reference.

Teach pendant code used to actuate the gripper

user:~$ rosservice call /write_single_io 10020 1
message: ''
success: True
user:~$ rosservice call /read_single_io 10020
message: ''
success: True
value: 1
user:~$ rosservice call /read_single_io 10021
message: ''
success: True
value: 0
user:~$ rosservice call /read_single_io 10022
message: ''
success: True
value: 0
user:~$ rosservice call /read_single_io 10023
message: ''
success: True
value: 0
user:~$ rosservice call /read_single_io 10024
message: ''
success: True
value: 0
user:~$ rosservice call /read_single_io 10025
message: ''
success: True
value: 0
user:~$ rosservice call /read_single_io 10026
message: ''
success: True
value: 0
user:~$ rosservice call /read_single_io 10022
message: ''
success: True
value: 0
user:~$ rosservice call /read_single_io 10027
message: ''
success: True
value: 0

[ted-miller]

OT#(10) is address 10021.
OT#(12) is address 10023.

The console commands shown above only do a write operation to 10020.

[Avgrobo]

Could you please explain what you are referring to by "The console commands shown above only do a write operation to 10020"? We use the rosservice /read_single_io to read the status of the address 10020 if i am not wrong.

Also, we did try the above mentioned address (10020) with both read and write commands, both didn't work (Gripper position didn't change) only the value changed between 0 and 1.

Do we have any specific logic or script to be followed to send or receive signals I/O?
Note: We tried the same after calling io_relay.launch

[ted-miller]

The GRIPPER job shown on the teach pendant uses 10021 and 10023. I expect that one (or both?) of these signals is controlling the gripper.

You should try /write_single_io with address 10021.

Do we have any specific logic or script to be followed to send or receive signals I/O?

No

[Avgrobo]

Thank you very much for your time and support. We've resolved issue for gripper control and the connection between ROS I/O and controller is working well.

@ted-miller @gavanderhoorn

[gavanderhoorn]

Good to hear you got things to work. Thanks for letting us know.