Hi Spencer,
The ModIO will work with some USB to RS232 converters. It depends on the driver for the converter. The Modbus RTU specification requires a delay at the end of a command to the Modbus slave in order to detect the end of the message.
If the converter driver buffers up a number of requests, then bursts them to the slave is a continuous transmission it will not be adhering to the Modbus specification, causing the slave (ModIO) to detect an error, and reject the commands.
That said, a lot of the cheap Chinese converters work fine. Also some drivers allow you to set the buffer to be very small to that buffering does not occur.
so it's a bit of suck it and see.
If you use Modbus ASCII format, there is a character at the end of the command that the slave can use to detect the end of the command. The ASCII format is not very efficient, and the ModIO does not support it.
Cheers,
Peter
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On 2020-02-17 04:08, spencer@... wrote:
I looked at the manual; and it does not look like you can change the
display configuration. This would be highly unlikely. I have
programmed microcontrollers with similar dis[plays and it is a genuine
bitch to get everything in the right place on such a small display let
alone provide different and smaller number of characters. These
disoplays are really easy to find surplus now because most people have
moved to graphic displays. Unless you are really in the boonies you
should be able to get one quickly?
What is the reason for the Modio as opposed to parallel port types or
more modern ones that use network or USB? I am not crazy about my
setup although it does seems to be working and am considering what to
try next for a BOB? Would rather not get stuck with legacy computers
although I do have a pile of Optiflex. Is the modio supposed to work
with USB to rs232 adapters? I did not see anything about that in the
manual?
Best regards, Spencer Chase
67550 Bell Springs Rd.
Garberville, CA 95542 Postal service only.
Laytonville, CA 95454 UPS only.
Spencer@...
Spencer@...
Spencer@...
(425) 791-0309
(707) 223-8212
------ Original Message ------
From: "John Dammeyer" <johnd@...>
To: [email protected]
Sent: 2/16/2020 12:55:20 AM
Subject: Re: [MachCNC] MODIO LCD
So it doesn't like a 12V power supply when connected to the PC. Raise the input voltage to 15V and it stabilizes. Turn the encoder one click and the start up screen changes to one with all sorts of information spread out in a strange way. What I can see is the MPG-1 value change as I rotate it. As for the other numbers I don't know what they are.
Is there a way to tell the MODIO that I have a 16x4 display? Or will I have to wait until the correct display arrives?
Thanks
John
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of John
Dammeyer
Sent: February-15-20 6:05 PM
To: [email protected]
Subject: [MachCNC] MODIO LCD
Well crap! Really must learn how to read. I was so excited when my 2 LCD
displays arrived on Thursday. Today I carefully soldered on the ribbon cable
and crimped the 16 pin socket onto the other end. Then plugged into the
MODIO and applied power.
It lit up. But all sorts of odd blinking and the error light coming on while it's
connected to MACH3. Unplug MACH3 and it stabilized. So that's problem #1.
Problem #2 is much worse. The characters weren't all in the correct spots
and some appeared to be missing. A quick count showed the display was 16
wide, not 20. A look at the order online showed I'd ordered 16x4 displays.
Sigh... I've re-ordered two 20x4 but with shipping this project has been
shifted sideways by a month or two now. Or earlier if they come earlier.
John Dammeyer
