Dmx address Glitch!

[Fountain Craft MFG.]

I need  some help with a vary odd issue.
I use a BX-DM1E variant in my Fountain Control Panels with a Serio Card to out put both DMX to control the Color Changing Lights, And MODBUS to Control the Pump VFD's.
the issue I'm having is when the Modbus commands are active the Upper DMX Addresses 319 and up stop updating and any thig above 256 is intermittent. the real issues is for the domore software data view the id no indication of this. the only way to see it is by looping a master port to a slave port. as soon as you stop the Modbus it goes a way. ADC was at a loss as to the problem. it definitely is not my ladder code, ADC confirmed.

i will thro to gather a simple example and upload

i think it is a operating system issue

[franji1]

So you are not using the onboard serial for anything, and you are using like Port A for DMX Master and Port B for Modbus Master on your SERIO?

[Fountain Craft MFG.]

Here is my example program

[Fountain Craft MFG.]

Im using the onbord seral and C&D on SERIO as Modbus master for 3 vfds each. and B is DMX Slave A is dmx Master.

[MikeS]

so there's 9 VFDs in your system (3 serial ports with 3 drives each) ? if so, that's a potential source of a lot of electrical noise.

try to eliminate that as the problem by enabling only one VFD and see if the DMX port works properly. if so, add VFDs one at a time and see if/when the DMX comm problem manifests.

[Fountain Craft MFG.]

the issue show up on my bench test mockup with no vfd's connected.

i just now got around the issue by offsetting the Modbus commands by 30 ms. i was writing to both ports at the same time. i think it was causing a internal collision of some kind. c and d now alternate sending every 30ms. and updating A dmx every 25ms. it seams to be working. it was just odd that you could not see it in the data view, you had to read the actual out put signal.

[MAEdwards]

Fountain Craft MFG, Is this the same issue?
https://forum.hosteng.com/index.php?topic=3540.msg26959#msg26959

[BobO]

Fountain Craft MFG, Is this the same issue?
https://forum.hosteng.com/index.php?topic=3540.msg26959#msg26959

Almost certainly is.