MOC5007 Optocoupler drop-in replacement

Started by Shane williams in comp.arch.embedded8 years ago 5 replies

Hi We're using the MOC5007 opto-coupler for isolation in an RS485 circuit. Does anyone know of a drop-in replacement for this with slightly...

Hi We're using the MOC5007 opto-coupler for isolation in an RS485 circuit. Does anyone know of a drop-in replacement for this with slightly better performance? The pinouts are shown halfway down this page http://www.datasheetdir.com/MOC5007+Optocouplers TIA


RS232/485 impromptu survey.

Started by Not Really Me in comp.arch.embedded14 years ago 20 replies

How popular is that old standby async/sync serial data in new embedded designs? I know there are lots of other technologies coming into play...

How popular is that old standby async/sync serial data in new embedded designs? I know there are lots of other technologies coming into play from ethernet to wireless, USB, etc., but what percentage of your new designs are using RS232 or RS485? I still see it on almost every project. If not as an intended interface then at least for debugging. Your comments are appreciated. Scot...


What Serial Link to use

Started by Jalon in comp.arch.embedded11 years ago 6 replies

Hi All, I am a novice in Embedded and looking for inputs on the Basic characteristics of serial protocols that will help me in deciding...

Hi All, I am a novice in Embedded and looking for inputs on the Basic characteristics of serial protocols that will help me in deciding which protocol to use (SPI/SCI,I2C..... RS485, RS432). In other words i find easy to understand these protocols individually but when it comes to design/architect a system what points will help me in going one of these protocols. Thanks a ton in advance...


UART speed problem

Started by Jack in comp.arch.embedded10 years ago 11 replies

Hi, I need an opinion: a customer wish to comunicate with our board (that uses a Freescale MC56F8037 to control a BLDC motor with hall sensor...

Hi, I need an opinion: a customer wish to comunicate with our board (that uses a Freescale MC56F8037 to control a BLDC motor with hall sensor for commutations and an encoder for position sensing) via a RS485 bus with a baudrate of 230400 bps. the frames are 16byte in length and a reply is expected within 3 msec (communication should be every 80 msec). I'm not sure that the 8037 can hand...


Modbus device ID

Started by Anonymous in comp.arch.embedded12 years ago 1 reply

The company I work for is developing a controller that has three communications ports: two RS485 and one TCP. Modbus TCP and Modbus RTU...

The company I work for is developing a controller that has three communications ports: two RS485 and one TCP. Modbus TCP and Modbus RTU Master/Slave will be implemented. It has been proposed that each port have a different Modbus device ID, rather than one global ID. I contend there is no benefit to this, and only adds confusion for integrators. Does anyone know of a precedent for this?...


RS485 is too expansive: any replacement?

Started by Anonymous in comp.arch.embedded12 years ago 4 replies

Hi, I'm called to design a multi drop network where the nodes communicate using 2 wires. The distance from 2 nodes is maximum 20 meters....

Hi, I'm called to design a multi drop network where the nodes communicate using 2 wires. The distance from 2 nodes is maximum 20 meters. The wires will run along the mains (220 V). I requested a quotation for the following part: MAX3483ECSA (3 Volt, ESD protetected, transceiver) and they told me that 4000 parts cost 1.90 Euros each... amazing! Are there...


4.3"-5" TFT display suggestions

Started by pozzugno in comp.arch.embedded5 years ago 3 replies

It's difficult to find a read-to-use 4.3"-5" tablet/photoframe/panel PC/others at low-cost (50USD) for quantity (1k-5kpcs) that is hackable...

It's difficult to find a read-to-use 4.3"-5" tablet/photoframe/panel PC/others at low-cost (50USD) for quantity (1k-5kpcs) that is hackable with a custom firmware/software for my application that requires just the display and a RS485 two-wires ports. I tried to contact some Chinese photo frames manufacturers, but they aren't available to let me install a new firmware and it's diffult to...


Monitor RS232 comms with millisecond resolution

Started by rowan.bradley in comp.arch.embedded9 years ago 75 replies

Anyone know the quickest or easiest way of recording a serial data stream and timestamping each byte with a resolution of at least 1ms...

Anyone know the quickest or easiest way of recording a serial data stream and timestamping each byte with a resolution of at least 1ms (preferably finer)? I can only find cheap or free programs with less resolution, or very expensive solutions, often involving special hardware. I only need to monitor one port, and I don't need to send any characters (actually I'm snooping on an RS485 bus). ...


Empty Hub Enclosures?

Started by Mike V. in comp.arch.embedded15 years ago 12 replies

I want to make a board that has: 1. ethernet socket 2. two rs232 ports 3. one rs485 ports And put an enclosure around it. Do you guys know...

I want to make a board that has: 1. ethernet socket 2. two rs232 ports 3. one rs485 ports And put an enclosure around it. Do you guys know of any enclosure companies that sell plastic enclosures that look like your small typical Netgear or Linksys hubs, which i can just get the holes cut out? I need that "cool" look, rather than just going to Digikey and getting a simple plastic rectangu...


Request about Ethernet node

Started by Capoccetta in comp.arch.embedded14 years ago 2 replies

Hi, we have been asked to develope a simple Ethernet I/O node; the board should be able to send input status and receive output configuration...

Hi, we have been asked to develope a simple Ethernet I/O node; the board should be able to send input status and receive output configuration via Ethernet packets. This would be our first project including Ethernet (we have already designed similar systems based upon RS485 or CAN networks); any suggestions about basic books/faq/documentation? We normally use AVR and Renesas 300H in our desig...


RS 485 wiring with CAT5 cable

Started by 1206.sachin in comp.arch.embedded11 years ago 4 replies

I am using RS485 bus with 8051 which is working fine ( one master & 13 slaves) My problem is how to wire these slaves using CAT5 cable which...

I am using RS485 bus with 8051 which is working fine ( one master & 13 slaves) My problem is how to wire these slaves using CAT5 cable which single stranded. At every slave the there is T joint to CAT5 cable How to make this joint very reliable.


error detection rate with crc-16 CCITT

Started by Shane williams in comp.arch.embedded8 years ago 77 replies

Hi We're using the 68302 micro with DDCMP serial protocol over two wire RS485. According to the user manual, this uses CRC16-CCITT -...

Hi We're using the 68302 micro with DDCMP serial protocol over two wire RS485. According to the user manual, this uses CRC16-CCITT - X**16 X**12 X**5 + 1. Does anyone have any idea what the chance of getting an undetected error is with this protocol? I know all single bit errors are detected. Supposing we run a point to point connection at slightly faster than it's really capable o...


DDCMP and 68302

Started by Anonymous in comp.arch.embedded1 year ago 3 replies

Does anyone know anything about DDCMP and the 68302 chip. We have some software that uses it in asynchronous mode over RS485 and we want to see...

Does anyone know anything about DDCMP and the 68302 chip. We have some software that uses it in asynchronous mode over RS485 and we want to see if we can emulate the DDCMP behaviour on another product without the 68302 micro so that we can communicate with the existing product but from a new device with a different microprocessor. The 68302 manual says that in asynch mode when i


CPU recommendations?

Started by Anonymous in comp.arch.embedded10 years ago 54 replies

Hi All, I'm starting a new embedded control project soon, it looks fairly simple so far, read some analog and digital inputs and provide...

Hi All, I'm starting a new embedded control project soon, it looks fairly simple so far, read some analog and digital inputs and provide some PRM, digital & serial RS485 outputs. Sampling at about 10Hz should be sufficient. I'm thinking a lower speed 16 or 32bit CPU will do the job. I'd like to use a CPU which: supports source level debugging & fast code download for rapid turn aro...


TCP/IP Stacks for STR9

Started by dadams in comp.arch.embedded11 years ago 7 replies

I am working on new design on the STR9 that requires Ethernet. I have very little knowledge of Ethernet, as on previous applications we...

I am working on new design on the STR9 that requires Ethernet. I have very little knowledge of Ethernet, as on previous applications we have transmitted data (in a variety of protocol formats such as Modbus, DNP3.0) serially using RS485. We are now wanting to do this over Ethernet, and there seems to be several TCP/IP stacks available. As I only require to send and receive data I was wo...


DIY avionics (Was: Micro with CAN + drivers)

Started by Roberto Waltman in comp.arch.embedded7 years ago 4 replies

Dave Nadler wrote: > Looks nice ! From a distance. When you get close you begin to notice the calluses and warts. It is sill a good...

Dave Nadler wrote: > Looks nice ! From a distance. When you get close you begin to notice the calluses and warts. It is sill a good airplane. > Here's my front office view: > http://www.nadler.com/public/YO_FrontOffice.JPG > Top center instrument (I designed) uses RS485 You mean the yaw string? ;) [ The ILEC in the panel looks nice too. ] > Maybe a dumb question, but given your inte


How to read a 32-bits hw counter on 8-bits microcontroller

Started by pozzugno in comp.arch.embedded5 years ago 8 replies

In the thread above about RS485 driver enable, always originated by me, some new and interesting (for me) techniques has been descripted to use...

In the thread above about RS485 driver enable, always originated by me, some new and interesting (for me) techniques has been descripted to use a "wide" (32- or 64-bits) hardware up/down counter to read effectively without disabling interrupts, as I usually have done in the past. If the processor supports native hardware 32-bits counter, the problem doesn't exist: most probably it can b...


Ford DCL protocol

Started by Jeroen in comp.arch.embedded13 years ago

does anyone know the protocol of Ford's DCL (data communications link) used on early '90s EEC-IVs? It's a two pin connection (it's not the...

does anyone know the protocol of Ford's DCL (data communications link) used on early '90s EEC-IVs? It's a two pin connection (it's not the normal flash self test flash code thing); from patents I've found it's probably a RS485 connection but I can find no info about the protocol used, other then a few scan tools that support it. Thanks


RS485 - MODBUS or PROFIBUS or ....

Started by eeboarder in comp.arch.embedded10 years ago 44 replies

I am going to work on a project involving multiple devices on the same network(3 or more). One device will have user input and...

I am going to work on a project involving multiple devices on the same network(3 or more). One device will have user input and display(master). The other devices(slaves) will just collect sensory data and possibly process PID control loops. Data speeds are not a priority( < 1Mbps is okay). The master will read data from the two slave devices, and it may have to change manipulate data on the sla


Embedded Linux: share data among different processes

Started by pozz in comp.arch.embedded3 years ago 48 replies

I'm new to embedded Linux so this question could be very simple for many of you. Most probably, it isn't directly related to embedded world, but...

I'm new to embedded Linux so this question could be very simple for many of you. Most probably, it isn't directly related to embedded world, but to Linux OS generally. Anyway I think it is a common scenario in embedded applications. I'm going to develop a local/remote control of an electronic device. It communicates through a RS485 link. The local control will be a touch-screen display...