ITTSB.EU Blog Forum
AC Power Meter | PSU | UPS evaluation | Battery Testers - Chargers | CCTV => Bench-top Single Phase Power Meter => Topic started by: Kiriakos GR on October 29, 2024, 07:09:50 PM
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industrial USB to RS232/485/TTL isolated converter, this is a special purpose gadget.
I came across of a digital power meter factory, which them skipped to equip their instruments with isolated communication ports of USB and or RS-232 and or RS-485.
And they now force potential buyers, them to purchase an external communication isolated box from them.
Their pack of offerings includes single conversion solution, from instrument output connector to RS-232, or USB or RS-485.
And their boxes has inflated pricing too.
Since the beginning of 2019, Waveshare Electronics this has dominate this market, by a single offering this loaded with a combination of ports.
And in my case, Waveshare isolated communication controller, this is 25% cheaper than the offering of digital power meter factory.
Waveshare using FT232RL, FTDIPORT.INF year 2015.
Operating system: Windows 10 / 8.1 / 8 / 7 / XP
And compatibility extends even at Win 11.
https://www.waveshare.com/wiki/USB_TO_RS232/485/TTL (https://www.waveshare.com/wiki/USB_TO_RS232/485/TTL)
I am planing to get a bench-top digital power meter for my lab, and I am exploring all my options about having an isolated communication link with my PC.
In the positive side of things, I do read only positive user reviews, about this Waveshare product.
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Waveshare SKU:15817
This using technology of 5/2021 8)
2Pai Semi digital isolators product family.
PAI 141E61 chip (PAI = Greek alphabet for P)
People, this chip has a pile of fresh and plenty of certifications.
And Waveshare marketing team, this is not familiar with electronics components, so to better explain product details.
Below are photographs, my work, these presenting in brief of what PAI 141E61 this is capable to do. ;)
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Another minor mystery this solved today due Waveshare customer support team and (Ms Silvia).
Part: USB TO RS232/485/TTL
USB cable length = 1.2 meters
Latest FTDI Chip Driver ( Windows (Desktop) 15-07-2021 V2.12.36.4 WHQL Certified (last check 11/2024)
https://ftdichip.com/wp-content/uploads/2023/09/CDM-v2.12.36.4-WHQL-Certified.zip (https://ftdichip.com/wp-content/uploads/2023/09/CDM-v2.12.36.4-WHQL-Certified.zip)
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At my new application, from Waveshare SKU:15817, I did use TTL 5V port as Input, and the USB port as Output.
My host device, this has internal supply of 5V DC (4,92V), and I did connect all four wires TX, RX, VCC, GND.
Note: It is interesting that Waveshare (device) onboard LED indicators did not show any indication that TTL 5V this is connected.
But when USB port becomes active (when this is connected to PC).
Onboard LED indicators they become active.
PWR: Red power indicator, light up when there is USB connection and voltage is detected
TXD: Green TX indicator, light up when the USB port sends data
RXD: Blue RX indicator, light up while the device port is receiving data
This is my first TTL to USB converter, and I did succeed five measurements /S, logged as max per single measurement.
And when TTL port started to receive a larger stream of data, communication rate this become three measurements /S
:)
Note: The only problem that I need to solve, this is TTL wires protection, because my application is portable, and cabling this is not secured within a cabinet.
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This is probably my last mention about this Waveshare product.
I did note that VCC for TTL this was poorly documented, if this is input or an output?
And the truth was hidden at Waveshare FAQ.
Question: What is the VCC function?
Answer: VCC is the power supply pin, which can be switched by 5V or 3.3V (50mA) to power the connected device.
If the device already has another external power supply, it can be connected without VCC.
And therefore I need to disconnect / remove the VCC wire, because my host device this is self powered.
;)
Actual VCC output: 5.180 V or 3.267 V (with out load)
And here is the most rare to see item on the web, the carton box.
Just two nylon bags inside and no product documentation included. :P
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So now you are also become a TTL systems communications Expert 8)
How can we know best USB baud rate setting, when from the other end is a TTL port?
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So now you are also become a TTL systems communications Expert 8)
How can we know best USB baud rate setting, when from the other end is a TTL port?
Excellent question!
But the answer, this is a very expensive one.
Here is the sort version: At electronics design, UART Chip / port, the communication baud rate this is set by the use of another external component.
Due visual inspection of the HOST circuit and around the MCU, according to specific part value used, there is a relative chart about supported baud rate.
I came across this detail, when I was reading documents about the architecture of UART Chip, from several brands.