Questions tagged [rs232]

RS-232 is the electrical standard used on most serial ports. Note that this standard is a +/- 15 volt system and requires a FDMI converter to make it compatible with TTL logic levels.

Filter by
Sorted by
Tagged with
0
votes
2answers
49 views

Bi-Directional RS-232 / RS-485 translator using MAX3162 IC

I'm trying to communicate with an I2C bus using the Serial Card in my PC (NI PCI485/8). I've created a circuit using the MAX3162 to translate from RS485 to RS232. Then I use the MAX3232 as a level ...
0
votes
0answers
26 views

RS232 to RS485 converter for RS422 conversion purpose [closed]

I want to use RS232 to RS485 converter for RS422 to RS232 conversion , by connecting RS422 on the RS485 side. Is this a mistake ? Can you also exaplain if yes or no ?
6
votes
2answers
788 views

History question - why are logic levels inverted between TTL and RS232?

I'm just looking for a historical answer as to why TTL and RS232 don't transition logically in the same directions. The signals are the same, but basically level-shifted and inverted. Was there a ...
2
votes
1answer
56 views

What kind of serial cable do I need? (TTL vs RS232)

So I have a headless NAS that I'm trying to connect to via a serial console so I can install a different OS. It has a 3.5mm jack on the back I/O labeled COM1. I had ...
0
votes
0answers
26 views

Chip shorting to ground when connecting the grounds

I have a pcb that converts USB to RS232, it is using a CH340G and a MAX2323. The output when not connected works as expected. I try to connect it to a separate device that has its own power supply. ...
0
votes
0answers
18 views

Multidrop bus protocol on the BeagleBone Black PRU

I am truying to implement the MDB protocol on the BeagleBone Black, the problem is : the protocol requires a 9 bit data via UART (9th bit used to differentiate if the sent/received data frame is an ...
0
votes
1answer
64 views

Multidrop RS232 - Diode selection and doubts

i'm currently using this reference schematic to wire up 10 RS232 slaves in a "multidrop" configuration (The slaves are some ATMEGA328P with MAX232 Trancievers in order to make a real RS232 ...
0
votes
0answers
18 views

CANoe communication relais board via RS232

I am using Vektor CANoe 11.X and want to test a relais board. How do I set up a simulation to communicate with the relais board? I am connecting the 9 pole rs232 port via gender changer to vektor ...
0
votes
2answers
36 views

RS232 RFID reader not working

I have purchased an RFID reader that communicates using an RS-232 cable. I have however used an RS-232 to USB adapter to connect it to my laptop. It is an ACM812A RFID reader. When I open the RFID ...
0
votes
1answer
69 views

Sniffing an RS-485 communication

I am trying to sniff a serial communication between two devices. One of them sends a command (6 bytes + 2 bytes CRC), the other one responds (4 bytes + 2 bytes CRC). My computer monitors the exchange ...
2
votes
3answers
1k views

Why single ended signal line is not immune to noise in RS232?

In single ended signal line the measurement is the difference between the signal and the ground. Isn't this way of calculation make it differential? Almost all the resource I have read says that ...
0
votes
1answer
32 views

GSM DCE to TCP - mocking a GSM modem

I'm trying to interface a device (Opentherm thermostat) that actually supports to be controlled through SMS via a serial connection to a GSM modem. I'd like however to control it through TCP rather ...
1
vote
2answers
78 views

Interfacing stm32 with MAX232

I am interfacing MAX232 with STM32F030k6. I have very recently found out that Max3232 would be a better choice, because it works with 3,3 volt. But I am eager to know if UART reciever pin of the ...
0
votes
0answers
44 views

RS232 comm problem

I have two devices (Lambda power supply and custom controller) that communicate via RS232 at 9600 baud using 3 wires. A direct connection does not work properly (PS doesn't respond) but if I connect ...
0
votes
0answers
34 views

Power loss shutdown occurring with Pico UPS

I'm currently suffering from issues where my raspberry pi appears to lose power over time and shut down (I'm using a pico UPS to handle file safe Shutdown). From the symptoms i'm seeing it appears ...
0
votes
0answers
22 views

How to store data in Keithley2400 buffer during measurements and retrieve through rs232?

I am trying to do an IV measurement (source current, sense voltage) store into the Keithley2400 buffer and retrieve the measured data (voltage and current) into my python program variable 'data'. <...
0
votes
1answer
50 views

Trying to work out the pinout of an RJ10 (or RJ 11) RS232 port,

New here so please bear with me ;-) I have a salt chlorination system for my pool, which includes a unit that tests the water for Chlorine and PH. It has an 'RS-232' port on it, which is supposed to ...
1
vote
1answer
60 views

RS232/CAN switch circuit

I am working on a communication switch that is digitally controlled and I am using four MUX506IPWR from TI to choose the output channel. The switch has on the input a DSUB9 for a CAN channel and a ...
1
vote
0answers
26 views

UART communication with a Thorlabs chip

I am trying to configure a Thorlabs temperature driver (MTD415TE), using a UART-USB connection. For this, I am using a Foca v2.2 with a FT232R USB-UART cable. I am using serial terminals such as ...
0
votes
0answers
14 views

XPort Edge (web manager) access denied with default credentials

I have the Xport EDGE connected and powered using the evaluation board. I'm trying to use an XPort EDGE as a means of connecting an embedded device to the internet. It uses RS485 (That's the ...
0
votes
1answer
41 views

Frame Errors (Character Stretching) of CP2102N

When I send a data stream from my PC to a CP2102 USB-to-Serial Bridge, the data coming out of the RS232 side is sometimes corrupted. The receiving micro (an ATmega2560) reports frame errors when this ...
0
votes
2answers
85 views

RS232 Communication Voltage Level

I understand that RS232 Communication voltage levels should be between 3 and 25 Volts for positive voltages and the equal negative for negative voltages, but is there a source that can explain the ...
0
votes
1answer
81 views

Garbage on RS232 and no the baudrate IS correct

I have a device like this https://www.vaisala.com/sites/default/files/documents/WXT530-Users-Guide-M211840EN.pdf. Some facts: I have an FTDI to USB board from Sparkfun which is tested to work with ...
1
vote
1answer
47 views

Confused with PC RS232 pin-out for this stepper motor communication

I'm planning to communicate with the module of a servo motor. The manual is given here. At page 88 there is a diagram for RS232 wiring as shown below: The manual mentions in the motor side pin3 must ...
0
votes
1answer
47 views

ICL3232 and SN75C3232 difference

I'm using ICL3232EIV-16Z-T in one of my projects for UART communication. As per the datasheet, the max speed is 500Kbps. But I've tested this IC for baud rate up to 921600 and there is no data loss. ...
0
votes
1answer
14 views

Flashing LPC1769 with FlashMagic

I'm encountering problems flashing my LPCxpresso1769 with FlashMagic. I had previously been able to get it to work using a USB to UART lead (TTL-234X-3V3) and powering the device externally (i.e. ...
-1
votes
1answer
80 views

is it possible transfer an image via rs-232 serial-port cable? [closed]

*I want to take an image from a medical device. Should I take the data first and then visualize it in pc via another program?
0
votes
2answers
80 views

1-channel GPIO from industrial PC over RS232 port

I am ordering a computer based on 4x4-R1000V motherboard (Ryzen Embedded, https://www.asrockind.com/overview.asp?Model=4X4-R1000V) for an industrial application. I need a 1-channel GPIO (0 for zero, >...
0
votes
1answer
141 views

RS232 Modbus to USB wiring

I have a RS232 device that sends data following the modbus protocol. I have problems communicating with it and I think my wiring is wrong. Since most modbus devices work over RS485 it is hard to find ...
0
votes
4answers
121 views

FTDI (FT232R) chip holding the RX line high

The issue that I am having is that the device won't communicate. I have traced the problem down to the RX line on the FTDI chip holding itself high and not letting signals through. I have spent a ...
1
vote
0answers
89 views

MON08 RS-232 Programming Interface

I'm trying to build a MON08 interface to program a 68HC908QB8, as per page 13 of this PDF: Low-Cost Programming and Debugging Options for M68HC08 MCUs Below is my schematic, from which I have ...
0
votes
1answer
35 views

RS232 Serial Console: Do we receive serial packets at serial pin out from CPU even we don't have the console cable connected?

What if I don't have the serial cable connected to the serial port, still I receive serial packets from CPU? (lets say console output is enabled in Software) Will those packets got terminated (...
1
vote
1answer
90 views

Modbus RTU over RS232 link

I am designing a convertor board that will interface three device with Modbus RTU RS232 port to a Modbus RTU RS485 network. Slaves supports Modbus RTU, but their ports is different from master port. ...
0
votes
0answers
70 views

How to handle RS-232 grounding when connecting multiple devices?

I need to connect multiple devices using RS232 in a ring where the TX of one device goes into the RX of the next device. I will use a copper cable for the physical layer. I can't use RS485 that ...
0
votes
0answers
30 views

How can I connect multiple modules/devices to one single usb port

Currently I have one GSM IOT-GA6 module connected to my laptop using a CP2102 usb adapter. Currently im able to communicate with the device sending AT commands using ...
0
votes
4answers
291 views

RS232 Voltage Level Boosting

I have a piece of old instrument circa 1988 that uses +-12V in its serial port. According to the manual, DTR pin (Data Terminal Ready) must be held at +8V in order for the instrument to recognize that ...
0
votes
1answer
81 views

RS-232 to RS-485 transceiver

I'm new in communication protocols and ICs. I would like to know if it is possible to connect a RS-232 (TX, RX and GND) to a RS-485 (Vcc, A, B and GND). I only need a half-duplex communication. The ...
0
votes
2answers
621 views

Modbus RTU using SoftwareSerial

Im trying to control a temperature controller using Arduino MEGA over SoftwareSerial. Im using Modbus-Master-Slave-for-Arduino library and I tried to test using example code below. It gives only <...
0
votes
1answer
248 views

Connect to a serial output device with 12V power input with 5V USB-TO-UART

I have DG600F coin acceptor with 12V power input and serial port output CP2102 usb-uart bridge and FDTI TTL-232RG cabel as an alternative A PC and Macbook as alternative I need to connect DG600F to ...
0
votes
1answer
74 views

How to identify 422 or 485 bus from the PCB

I have a very old CPU card, maybe 1980's. It has following chips on it and most probably these are used for communication with the rest of the system. SN55188 Quad Line Drivers SNJ55189 Quad Line ...
0
votes
3answers
109 views

Connecting 2 external PCBs with a 1m cable

I would like to connect 2 PCBs. On each PCB there is a MCU and each MCU is able to send and receive commands from the other one. Also, PCB1 should supply power to PCB2. The 2 PCBs are separated by ~...
0
votes
2answers
73 views

RS232 to ethernet over LAN

Can I connect an rs232 Ethernet converter to a switch and expect to receive a data on a php server listening to the of IP conversor? In windows I need to install drivers to create a virtual com, so I ...
1
vote
1answer
632 views

RS422 and RS485; full-duplex or half-duplex?

I have extensively used RS232 transceivers in many projects and have fairly good understanding of UART communication using RS232 transceivers. MAX232 and MAX3232. Now I have to build my understanding ...
0
votes
2answers
1k views

RS-232 to I2C communication [closed]

I'm trying to establish communication between two boards, one of which has an RS232 output and the other with an I2C input. I've looked for adapters online and the only ones I've found seem to be ...
0
votes
1answer
228 views

Comparing MAX3232 vs MAX232 for line length

Which parameter in the datasheets of the line drivers MAX3232 and MAX232 can tell about the maximum length of the line for their correct operation if all else is same for the two circuits, that is ...
0
votes
3answers
262 views

MAX232 Replacement

I have a circuit where a 12V square wave signal (a Profile Ignition Pickup signal from a Ford EDIS ignition module) was fed to an MCU via a MAX232 chip. My understanding of the MAX232 is that the ...
0
votes
1answer
122 views

Connector Identification on Instrument

I have a piece of instrument made around 2000 with a connector to computer that I cannot recognize. Can someone help me out? It is a 20-pin connector, with 10 pins on each row. Pictures are here: ...
4
votes
2answers
314 views

RS232 Unusual “Framing Error”

I have an old piece of instrument that suppose to connect with a Windows XP machine. I keep getting "Framing Error" messages on the instrument panel while the PC side shows that the instrument could ...
0
votes
1answer
117 views

Detect an unknown communication protocol and read data on it

We have old type textile machinery in our factory. (open end machine) on the machine's screen is showing the operating efficiency of the machine. Under the hood, When I follow the cables, the sensors ...
0
votes
2answers
67 views

What specs does the “gros condo” (big capacitor) needs to have?

I have a pair of Dynaudio Air 20 at home. Unfortunately, the cable that used to control the speakers via RS232 died. I opened the cable, and saw that it was a customized RS-232 to TTL adapter, but ...

1
2 3 4 5
10