For the testing, we used this model of cable: https://www.amazon.fr/dp/B089FB2LRW?psc=1&ref=ppx_yo2ov_dt_b_product_details
On the WebUI, go to Managed Devices :: Devices :: usbS1: Access:
Keep the Type "usb_serialB" at its default value. Mode: set it to 'Enabled'. We keep the Baud Rate to its default (9600).
Optionally, you can enable the hostname detection and select an Icon corresponding to the vendor (here Cisco).
Click on Save.
On the main page, Access: the target device has appeared:
[admin@nodegrid /]# show /settings/devices/
There should be a new device with usb_local type, for example, usbS1-4. Then list its configuration:
[admin@nodegrid /]# show /settings/devices/usbS1-4/access
...
allow_ssh_protocol = yes
allow_telnet_protocol = yes
telnet_port = 7049
...
Telnet may be disabled. Try enabling it:
[admin@nodegrid /]# set /settings/services enable_telnet_service_to_managed_devices=yes
[+admin@nodegrid /]# commit
Then you should be able to 'telnet nodegrid 7049' or 'ssh -l user:7049 nodegrid'