Hello,

I have a system that have few components:

1 - Monarco with Rexygen and modbus driver
2- Coriolis flow controller with ModBus protocol
3- Analog data logger also controlled by Modbus protocol with a pressure transducer read by it
4- Servo actuated valve.

All the Modbus commands and data works fine. The signals from the flow controller, pressure transducer are linked to a TRND block. The ARC block is set.

The problem is that the data is not always correctly stored - even after correcting RTC issues, some experiments end at the wrong time stamps at the CSV file... Other times entirely groups of experiments just vanishes. I can not access the data from any other day besides the current one....

Please..... how is the correct way to properly set the ARC and TRND blocks to register the signals with good time resolution?

The current HMI window generated by the HMI designer is too small. Please is there a way to increase the size of it?

Thank you.

@reitinge With the "Duty_cycle = 1 - Calculated_duty_cycle" it worked like a charm. THANK YOU!

@reitinge said in RC Servo PWM control.:

Can you send a wiring diagram to your RC servo?

The signal wire of the servo is connect to the DOUT1. The servo is powered by a dedicated BEC to provide 6v that have a common ground with the Monarco.

I am also interested in this issue - I find the current HMI box too small - it shows a lot of screen around and I am using a standard full hd. I could not find a place to configure the size of the HMI interface.

@reitinge Thank you very much! That is what I am doing right now It works good enough.

Other doubt is about RW data and use of Goto and From.

If I have a RW type of register why I can not use the same register for both? Now I created a pair of them for this - one to write the value and a second one to read the current set value.

Thank you Jan

Swap Words did the trick:

There are other registers that I am not able to read even with the same settings (REGISTER_FLOAT type and Swap Words ticked)

Today I'll test the other way: try to write a float type

Ont he same subject, but other type of data, from the 917050-Manual-mini-CORI-FLOW.pdf page 29:

Type
Unsigned char 1 byte unsigned integer (0…255)
Unsigned int 2 byte unsigned integer, MSB first (0…65535)
Unsigned long 4 byte unsigned integer, MSB first (0…4294967295)
Float 4 byte floating point, IEEE 32-bit single precision, MSB first
Unsigned char '[x]' x byte array (text string)

This last one is a ASCII text . Please, any tips if it is possible to read or write these types of data? They give an example at page 35:

Fluid Name:
Request
01 03 81 88 00 05 2D DF
01 slave address of instrument Address = 0x01
03 function code 0x03 is Read Holding Register
8188 starting address
0005 quantity of registers (5 register2 = 10 bytes)
2DDF CRC

Response
01 03 0A 41 69 72 20 20 20 20 20 20 20 86 7F
01 slave address
03 function code 0x03 is Read Holding Register
0A number of Bytes
697220202020202020 Fluid Name in ASCII
86 7F CRC (Generated from the MODBUS slave)

Thank you!

Hello,

I am implementing a control solution for a breadboard rocket test bench using the Monarco HAT and Rexygen. I can read and write commands with success using modbus with all devices so far but I am having difficulties with some values that need to be read and write using 4 byte floating point (IEEE 32-bit single precision, MSB first) values.

How do I convert the read values to something human readable for my HMI and then convert analog inputs back to this format to send the correct command back?

For now the read values shows things like:

The upper one is a modbus value of temperature in the 4 byte floating point format and the lower one an integer of a second flow controller showing the same temperature. Just as an example.

Almost all commands and information I need does not need to be floating point but the critical input (the set-point of the controller) must be of this number format.

Thank you!

@reitinge And I am not sure...

At 50hz the servo just ignores the DOUT signal. It started working at 500Hz up to 5000Hz.

And the Duty cycle calculation does not create the expected response from the servo at all. The width I am sure (but it is around 0.8 to 2.2ms)

So I am confused. I could make the servo works but this formula for the duty cycle and pulse width does not works.