Mesa modbus and pktUart
06 Sep 2023 13:48 - 06 Sep 2023 13:49 #280102
by PCW
Replied by PCW on topic Mesa modbus and pktUart
1. That's active high TXEN (high when transmitting as expected)
2. The middle picture ( A,B ) doesn't seem to show any data
( if its at the same time per division as the other plots )
in fact it looks like the TXEN signal
2. The middle picture ( A,B ) doesn't seem to show any data
( if its at the same time per division as the other plots )
in fact it looks like the TXEN signal
Last edit: 06 Sep 2023 13:49 by PCW.
Please Log in or Create an account to join the conversation.
06 Sep 2023 13:52 #280104
by Donno
Replied by Donno on topic Mesa modbus and pktUart
Attachments:
Please Log in or Create an account to join the conversation.
06 Sep 2023 14:07 - 06 Sep 2023 14:08 #280105
by Donno
Replied by Donno on topic Mesa modbus and pktUart
I am using linuxCNC 2.9pre on raspberry i build latetest build and copied hostmot2.so and hm2_eth.so to make pktuart to work, could that cause problems ?
Last edit: 06 Sep 2023 14:08 by Donno.
Please Log in or Create an account to join the conversation.
06 Sep 2023 15:00 - 06 Sep 2023 15:07 #280109
by PCW
Replied by PCW on topic Mesa modbus and pktUart
I would say there are still hardware issues
(idle line state is undefined)
A must be high and B low when no one is driving the RS-485 bus
That's the reason for the 620 Ohm pullup on A and 620 Ohm pulldown on B
(idle line state is undefined)
A must be high and B low when no one is driving the RS-485 bus
That's the reason for the 620 Ohm pullup on A and 620 Ohm pulldown on B
Last edit: 06 Sep 2023 15:07 by PCW.
Please Log in or Create an account to join the conversation.
06 Sep 2023 16:16 #280116
by Donno
Replied by Donno on topic Mesa modbus and pktUart
Attachments:
Please Log in or Create an account to join the conversation.
06 Sep 2023 16:24 #280117
by Donno
Replied by Donno on topic Mesa modbus and pktUart
Attachments:
Please Log in or Create an account to join the conversation.
06 Sep 2023 16:50 #280119
by PCW
Replied by PCW on topic Mesa modbus and pktUart
Yes the circuit looks correct now
(I would remove the 120 ohm resistor if still there to get better idle levels)
(I would remove the 120 ohm resistor if still there to get better idle levels)
Please Log in or Create an account to join the conversation.
06 Sep 2023 16:57 #280120
by Donno
Replied by Donno on topic Mesa modbus and pktUart
Attachments:
Please Log in or Create an account to join the conversation.
06 Sep 2023 17:08 #280121
by PCW
Replied by PCW on topic Mesa modbus and pktUart
OK well at least now the hardware is correct so if the VFD is
not responding its likely something in the commands or serial
protocol that the VFD doesn't like.
Are you sure modbus is enabled on the VFD?
Have you tried different parity options?
(parity is not of much use since the packets have a 16 bit checksum)
If you set the mesa_modbus debug option to 3 you can see what is sent
to verify that it makes sense relative to what the VFD expects
not responding its likely something in the commands or serial
protocol that the VFD doesn't like.
Are you sure modbus is enabled on the VFD?
Have you tried different parity options?
(parity is not of much use since the packets have a 16 bit checksum)
If you set the mesa_modbus debug option to 3 you can see what is sent
to verify that it makes sense relative to what the VFD expects
Please Log in or Create an account to join the conversation.
06 Sep 2023 17:37 - 06 Sep 2023 17:38 #280124
by Donno
Replied by Donno on topic Mesa modbus and pktUart
Attachments:
Last edit: 06 Sep 2023 17:38 by Donno. Reason: spelling
Please Log in or Create an account to join the conversation.
Time to create page: 0.202 seconds