An RS232 cable question or two

Started by Anonymous in sci.electronics.basics5 years ago 15 replies

Greetings RS232 Gurus, I have a couple machine tools that connect to a computer through RS232. I now need to run a longer cable for one of the...

Greetings RS232 Gurus, I have a couple machine tools that connect to a computer through RS232. I now need to run a longer cable for one of the machines. Looking online it seems like the biggest limiting factor is the capacitance of the cable. I have a reel of cable with three twisted pairs and no shield that's about 300 feet long. Measuring the capacitance with my multimeter I find the capac...


RS232 cable followup

Started by Anonymous in sci.electronics.basics5 years ago 5 replies

Thanks again to those who responded to my RS232 cable question. This morning I soldered on the DB connectors and did a test of the cable. There...

Thanks again to those who responded to my RS232 cable question. This morning I soldered on the DB connectors and did a test of the cable. There were no problems. I fact, though this is really subjective, the program seemed to download faster than it did with the older, shorter, spliced cable. Eric


Chassis Ground layout for better ESD and EMI compliance

Started by Mark in sci.electronics.basics6 years ago 67 replies

I have 2 USB, 2 Ehthernet and 2 RS232 connectors on the PCB. USB conns are one side, Ethernet conns on the 2nd side and RS232 on the 3rd side of...

I have 2 USB, 2 Ehthernet and 2 RS232 connectors on the PCB. USB conns are one side, Ethernet conns on the 2nd side and RS232 on the 3rd side of the board. All are through hole connectors and on top layer with separate chassis ground area on each side for connectors shields. So I have three chassis ground islands on th board for three sets of these connectors. If we have to connect the chassi...


seven segment display

Started by Anonymous in sci.electronics.basics11 years ago 4 replies

Hello, I am attempting to find a (multiplexing)seven segment display driver capable of driving at least 5 7seg drivers. I have found...

Hello, I am attempting to find a (multiplexing)seven segment display driver capable of driving at least 5 7seg drivers. I have found many but it seems they all have a synchronized serial input like SPI, but most of them are I2C. I would imagine this is to make designing with a uC easier, but what if I want to hook it up to my computers RS232 serial port? Do they make chips that talk As...


Surge Protector - how they work?

Started by Kari Laine in sci.electronics.basics7 years ago 9 replies

Hi, it is the thunder season here in Finland so I got interested how these surge protectors are built - which say they will save you hardware...

Hi, it is the thunder season here in Finland so I got interested how these surge protectors are built - which say they will save you hardware from spikes - yeah.... Are there avalanche diodes and coils? I have a dim feeling I have asked this before... Best Regards Kari -- PIC - ARM - Microcontrollers - I2C - SPI Keypads - USB-RS232 - USB-I2C - Accessories http://www.byvac...


programming atmel chip

Started by freeze in sci.electronics.basics10 years ago 2 replies

i need to program the at89c51ed2(atmel chip). i am using the usb-rs232 for this purpose. all my circuit connections are properly wired...

i need to program the at89c51ed2(atmel chip). i am using the usb-rs232 for this purpose. all my circuit connections are properly wired n everyhting recheked a thousand times. but still, the programming software that i use, in order to program the chip, gives me a 'connection time out' error. have tried all sorts of RESET dance that have been specified in the datasheet, but still no result.......


PIC MPLAB programmer I/F.

Started by ian field in sci.electronics.basics10 years ago 4 replies

Does anyone have any info on whether MPLAB has RS232 compatible programmer support? Having downloaded a number of programmer schematics, I've...

Does anyone have any info on whether MPLAB has RS232 compatible programmer support? Having downloaded a number of programmer schematics, I've found that a couple (Serpic & David Tait) that are very similar to the Velleman K8048 and wondered if this is some sort of industry standard. If anyone is interested, the examples including Velleman K8048 schematic are easy to find with google. ...


Simple circuit to measure baud rate on a serial link

Started by Simon in sci.electronics.basics11 years ago 8 replies

Hello - I'd like to be able to measure the baud rate that a couple of sealed devices are using to talk to each other over a serial (RS232)...

Hello - I'd like to be able to measure the baud rate that a couple of sealed devices are using to talk to each other over a serial (RS232) cable. I know that they only use the common baud rates 9600, 19200, etc. Can anybody give me some pointers on a circuit I could build that I could daisy chain with the serial cable to do this? A digital readout would be nice, but an analogue dial or s...


Serial Breakout Box

Started by Rolf in sci.electronics.basics3 years ago 3 replies

Looking for an inexpensive (less that $100) serial RS232 breakout box. Can set BAUD, etc and then receive serial data. needs to have some sort...

Looking for an inexpensive (less that $100) serial RS232 breakout box. Can set BAUD, etc and then receive serial data. needs to have some sort of data bit output; TTL or ?. up to 8 bits. nice to be able to send simple data byte back. A kit is fine. what's out there? I already have USB breakout boxes so that is not needed. --- news://freenews.netfront.net/ - complaints: news@netfr...