the load is an industrial isolation barrier. all measurements where done with the barrier disconnected and an amperemeter connected directly to the Neuron.
for test purposes I decided to download the demo application to my device. It is made for S10x and I am running it on a M203, but it shows the same behaviour:
rValue=0:
rValue=20:
rValue=157:
thanks for your fast reply!
I have changed the modbus mapping like your suggestion and send the data to the dac using my own scaling block, which works fine so far. my block scales my control value of 0-100% to a dac value of 0-2300 which gives me 0-20mA output.
as you mentioned any of these changes in the mapping has to be re-made each time there is an update in the device. therefore I would like to configure my block for an output value of 0-20 and send this value to the dac using the built-in function "SetAnalogOutput_mA".
And here comes the unexpected behaviour: rValue=0 gives 0mA output as expected (+low clipping message). but to get 20mA output I need a rValue of about 155 (without high clipping message). At rValue=157 the dac output is set to 2297... so I guess there is something going wrong with the scaling function...
Thanks for your help.
I now installed UniPian, removed the DS2482 DT overlay and replaced it by the owfs installation. At first i tried access with a manually configured modbus slave in codesys and everything worked fine. Then i ordered the UniPi for Codesys license and switched over to the Neuron Slave. Now I am a bit confused on how to setup the 0-20mA output. The word "wAOSettings" is set to "I_0_20" and I am trying to output the current with the "SetAnalogOutput_mA" function. For some reason I get an Output of 20mA when i call the function with a value of about 155 (mA?). The demo application shows the same behaviour.
please provide information on how to use the analog output properly. So far i did the scaling in my own software. i would also be fine to output the value as "raw value" for the DAC. how can this be done?
I am running CODESYS 3.5.12.20 and Raspberry PI 3.5.12.10.
The demo application shows the same error.
I am not using the UniPian Image, but the official Raspian Stretch operating system with fixed ip adress (dhcpd), W1 disabled, OWFS running and TCP modbus overlay for UniPi installed.(https://github.com/UniPiTechnology/neuron-tcp-modbus-overlay)
My idea was to build a combined alarm clock with internet radio (squeezelite) and light alarm clock (codesys controlled dimmer over pwm). For easier setup of OWFS and squeezelite I would prefer to stay with the official Raspian installation instead of UniPian.
Could you please provide the correct modbus configuration steps on Raspian needed for having access to the device?
I have been running the above system for the whole winter as heating controller and everything worked fine so far. For accessing the modbus tcp server I am using the function blocks from the OSCAT network library.
Now I want to add some more functions to my system which require faster access to the I/O's.
Therefore I tried the new codesys neuron package for I/O implementation but when configuring codesys like described in the manual I get the modbus error that the gateway does not reply.
When trying to add an modbus slave manually I get the same message.
Any ideas where the problem could be?
I am running a Neuron M203 with OWFS and codesys. Access to the 1W sensors works nicely by reading the data at OWFS's mountpoint using the sysFile library in Codesys.
But how can i access the I/O's? I guess using the modbus overlay is the solution. So Codesys needs to be the modbus slave... how can this be realized?