Hello,
I am trying to communicate with a resistance tester that will allow me to read the current resistance being tested via RS232. In order to get the current resistance reading, all I have to do is send any character to the device and it will reply with 5 character (numerals) plus a decimal point. The resistance reading take the for 'xx.xxx' (no delimiters)
The settings for the serial port are 9600,N,8,1. When I try communicating with the device in Hyper Terminal, I get the data back that I am expecting. Anytime I type any character on my keyboard I will immediately get a response of the form "xx.xxx " (it looks like there is a space between readings but it may just be Hyper Terminal appending this).
I am using a CompactLogix L32E controller to attempt to communicate with this device and I'm not getting anywhere. At first, I was using a 2 channel 1769-ASCII module to communicate with the device but was unable to get any response back.
I switched to using the on board serial port of the L32E and I am able to get 7 characters back from the device but they are bogus. A reading of 04.618 in Hyper Terminal shows up as $BF$B7$AF$B7$BB$BF when I use the PLC to communicate with the resistance tester. I assume that the $AF is representing the decimal point because it takes a different form than the other characters. But $AF is not even close to $2E which is the ASCII code for a decimal point.
I have tried changing a whole host of settings under 'user protocol' and 'system protocol' as well as changing the number of data bits to 7 (which gives '?7/7;=?'). I have set termination and append characters to null.
The others thing I have tried are:
- Changing control ine handshaking to full and half duplex
- Various different baud rates, parity bit settings, and stop bit settings
- Turning on 'XON/XOFF' and 'Echo Mode'
- Trying all three different 'Delete Mode' settings
Can anyone point me in a direction that may help???
Thanks!
I am trying to communicate with a resistance tester that will allow me to read the current resistance being tested via RS232. In order to get the current resistance reading, all I have to do is send any character to the device and it will reply with 5 character (numerals) plus a decimal point. The resistance reading take the for 'xx.xxx' (no delimiters)
The settings for the serial port are 9600,N,8,1. When I try communicating with the device in Hyper Terminal, I get the data back that I am expecting. Anytime I type any character on my keyboard I will immediately get a response of the form "xx.xxx " (it looks like there is a space between readings but it may just be Hyper Terminal appending this).
I am using a CompactLogix L32E controller to attempt to communicate with this device and I'm not getting anywhere. At first, I was using a 2 channel 1769-ASCII module to communicate with the device but was unable to get any response back.
I switched to using the on board serial port of the L32E and I am able to get 7 characters back from the device but they are bogus. A reading of 04.618 in Hyper Terminal shows up as $BF$B7$AF$B7$BB$BF when I use the PLC to communicate with the resistance tester. I assume that the $AF is representing the decimal point because it takes a different form than the other characters. But $AF is not even close to $2E which is the ASCII code for a decimal point.
I have tried changing a whole host of settings under 'user protocol' and 'system protocol' as well as changing the number of data bits to 7 (which gives '?7/7;=?'). I have set termination and append characters to null.
The others thing I have tried are:
- Changing control ine handshaking to full and half duplex
- Various different baud rates, parity bit settings, and stop bit settings
- Turning on 'XON/XOFF' and 'Echo Mode'
- Trying all three different 'Delete Mode' settings
Can anyone point me in a direction that may help???
Thanks!