Discrete I/O to Serial and Vice Versa
Discrete I/O to Serial and Vice Versa
(OP)
Hello,
I'm a mechanical engineer working in R&D at an aerospace company. I've been tasked with designing and developing a robotic system to offload some of the production at our facility. In the application I'm working on, I have a sensor that uses serial communication (RS-232) and I'd like to talk to it using the 8 channels of discrete I/O (8 inputs, 8 outputs) that my robot controller provides. I'd like to send signals both ways. My thought was that I could use 2 serial to parallel converters to do the job. One for talking to the sensor and one for receiving info from it (http://www.blackbox.com/Store/Detail.aspx/Serial-t...). The data coming through will only be a few bytes every 20 seconds or so giving x, y and positional data from the sensor.
First of all, does this look like a feasible plan? I've attached a block diagram of what I'm thinking.
https://res.cloudinary.com/engineering-com/image/upload/v1439926943/tips/150818134022_0001_cfct4v.pdf
On the connection between the DO and the P/S converter, I need to drop the voltage from 24V to 5 V. What would be a reasonable way to do this? On the other side I need to step up from 5 to 24V, I believe I could use an OP AMP here? My other question is on the connection to the sensor. Since I will need to switch between input and output to the sensor I would need to have some sort of switching mechanism to do this. Signals coming out of the sensor would go to one parallel to serial converter, and signals going in would come from the other. Anyone recommendations for the type of switch I could use to do this (type, brand, if possible Part Number). I would like to use a digital output to switch the switch from one side to the other if possible.
Trying to recall Electrical Engineering I learned in college 20 years ago =)
Anything else I may be missing?
Thank you for any help!
DJWilliams
I'm a mechanical engineer working in R&D at an aerospace company. I've been tasked with designing and developing a robotic system to offload some of the production at our facility. In the application I'm working on, I have a sensor that uses serial communication (RS-232) and I'd like to talk to it using the 8 channels of discrete I/O (8 inputs, 8 outputs) that my robot controller provides. I'd like to send signals both ways. My thought was that I could use 2 serial to parallel converters to do the job. One for talking to the sensor and one for receiving info from it (http://www.blackbox.com/Store/Detail.aspx/Serial-t...). The data coming through will only be a few bytes every 20 seconds or so giving x, y and positional data from the sensor.
First of all, does this look like a feasible plan? I've attached a block diagram of what I'm thinking.
https://res.cloudinary.com/engineering-com/image/upload/v1439926943/tips/150818134022_0001_cfct4v.pdf
On the connection between the DO and the P/S converter, I need to drop the voltage from 24V to 5 V. What would be a reasonable way to do this? On the other side I need to step up from 5 to 24V, I believe I could use an OP AMP here? My other question is on the connection to the sensor. Since I will need to switch between input and output to the sensor I would need to have some sort of switching mechanism to do this. Signals coming out of the sensor would go to one parallel to serial converter, and signals going in would come from the other. Anyone recommendations for the type of switch I could use to do this (type, brand, if possible Part Number). I would like to use a digital output to switch the switch from one side to the other if possible.
Trying to recall Electrical Engineering I learned in college 20 years ago =)
Anything else I may be missing?
Thank you for any help!
DJWilliams





RE: Discrete I/O to Serial and Vice Versa
Dan - Owner
http://www.Hi-TecDesigns.com
RE: Discrete I/O to Serial and Vice Versa
You can do it all with one input and one output, and some 'bitbanging' software.
(Most any really old microcontroller handbook will have examples of bitbanging a serial channel.)
I'd suggest optoisolators for the level translation, and a local EE to help you minimize the smoke leakage.
Mike Halloran
Pembroke Pines, FL, USA
RE: Discrete I/O to Serial and Vice Versa
Regards, Dustin
RE: Discrete I/O to Serial and Vice Versa
=about the 24 to 5 and 5 to 24V :
How much power / current do you need? does it has to be isolated ?
=About the communication ,
do u need to connect it with wires? what about using wireless wifi ? what is the range ?
What is the speed you need the data to flow ?
do you need it one way? or you want to have feedback from the robot?
Assume you have electrical/electronics engineers in your company they will love to help u
good luck-any response? daveross100@gmail.com
RE: Discrete I/O to Serial and Vice Versa
http://www.animatics.com/products/peripherals/anim...
-AK2DM
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"It's the questions that drive us"
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
RE: Discrete I/O to Serial and Vice Versa
16 pins of I/O.
One wouldn't have 16 I/O pins if trying to use a serial port as a discrete. It would work for some number of pins, but you'd need several serial ports to get 16 I/O pins in total.
Another approach would be to use an external uC such as an Arduino or Raspberry or any of the others. Plenty of I/O pins, easy software, and a serial or other connection to the PC.
RE: Discrete I/O to Serial and Vice Versa
DJWilliams
RE: Discrete I/O to Serial and Vice Versa