problem with usbtmc-communication

wrw at mac.com wrw at mac.com
Wed Dec 5 23:21:01 CET 2012


On Dec 5, 2012, at 3:38 PM, Jean Dubois <jeandubois314 at gmail.com> wrote:

[byte]

>> 
>> I note that in your Octave example you are reading characters rather than lines.  It seems to me that you have two choices here, either do the equivalent in python or dig through the Keithley documentation to find the hex codes that usbtmc is presumably translating your commands into.  If you can find those, and if you are interested, I can send you off-line the handler I wrote a couple of years ago that used a dictionary to translate English commands into hex, then assembled those with a checksum and sent the string out to a Keyspan usb to serial converter.
> 
> If you could show me how to "do the equivalent in Python" I'd
> appreciate that very much
> 
> best regards,
> jean
> -- 
> http://mail.python.org/mailman/listinfo/python-list

OK - I've excerpted some of the relevant code (the original was much longer and included a lot of error checking).  Please understand that the comments were for my own use, this was never intended to see the light of day (as it were).  Also, the structure grew from a situation where I only had to worry about a single controller model - single relay model to one where I had to be able to deal with two controllers and two relay models.  This was all python 2.7 of course.

........................cut on dotted line..........................
"""
 serial_port = /dev/tty.KeySerial1, 2, 3, etc.
 X10_controller = 1132B  or TI103
 Relay_model = UM506  or RBn04
 Relay_address = B2

"""
import serial, string

def checksum256(st):
    temp = reduce(lambda x,y:x+y, map(ord,st)) % 256
    if temp < 9:
        hex_temp = '0'+str(temp)
        return hex_temp
    hex_temp = hex(temp).upper()[2:]
    return hex_temp

letr_address_dict = {'A':'\x46', 'B':'\x4E', 'C':'\x42', 'D':'\x4A', 'E':'\x41', 'F':'\x49', 'G':'\x45', 'H':'\x4D', 'I':'\x47',  'J':'\x4F',  'K':'\x43',  'L':'\x4B',  'M':'\x40',  'N':'\x48',  'O':'\x44',  'P':'\x4C' }
numb_address_dict = {'1':'\x4C', '2':'\x5C', '3':'\x44', '4':'\x54', '5':'\x42', '6':'\x52', '7':'\x4A', '8':'\x5A', '9':'\x4E', '10':'\x5E', '11':'\x46', '12':'\x56', '13':'\x40', '14':'\x50', '15':'\x48', '16':'\x58' }
cmd_dict     =      {'SoC':'\x63', 'All_Units_Off':'\x41', 'All_Lights_On':'\x43', 'ON':'\x45', 'OFF':'\x47', 'Dim':'\x49', 'Bright':'\x4B', 'All_Lights_Off':'\x4D', 'Rep_Cnt1':'\x41', 'Rep_Cnt2':'\x42'}

def relay(port, controller_model, relay_model, relay_address, command):
    if controller_model == '1132B':
        if relay_model == 'UM506' or relay_model == 'UM7206':
            letr = letr_address_dict[relay_address[0]]
            numb = numb_address_dict[relay_address[1]]
            cmd = cmd_dict[command]
            cmd_string = '\x63'+letr+numb+cmd+'\x42'     # Start-of-Command + address_letter + address_number + command + Rep-count
            ser = serial.Serial(port, 9600, timeout=1)   # Set up handle to serial port
            stat1 = ser.write('\x02')                    # Write attention to PowerLink, stat = number of bytes written, not really an error return.
            ack1 = ser.read(2)                           # Check to see if PowerLink is ready
            if ack1 == '\x06\r':                         # It returns ACK<CR> (\x06\r) if it is
                stat2 = ser.write(cmd_string)
                ack2 = ser.read(19)
                if command == 'ON' and ack2 == 'XN\\1\rXNE1\rXNE1\r' : status = 0
                if command == 'OFF' and ack2 == 'XN\\1\rXNG1\rXNG1\r': status = 0
                if command == 'ON' and ack2 != 'XN\\1\rXNE1\rXNE1\r' : status = 1
                if command == 'OFF' and ack2 != 'XN\\1\rXNG1\rXNG1\r': status = 1
            elif ack1 =='\x15':                           # PowerLink sends NAC (hex 15) if it isn't.
                print('Received NAK from X10 Control, is there too much X10 traffic on the line?\n')
            else:   print("Something's wrong with X10 control. Ack returned was: " + ack1 + "\n")
            stat3 = ser.close()                          # Close serial port
            return(status)
 
---------
some irrelevant stuff was here, snipped
---------
    elif controller_model == 'TI103':
        if relay_model == 'UM506' or relay_model == 'UM7206':
            letr = relay_address[0]
            numb = relay_address[1]
            if int(relay_address[1]) <= 9:   numb = '0'+numb

#           stat1 = ser.write('$>28001B02B02 BONBONCC#') # Tell TI103 to send "On" to device B2

            ser = serial.Serial(port, 9600, timeout=0.1)   # Set up handle to serial port

            cmd_string = '$>28001'+letr+numb+letr+numb+' '+letr+command+letr+command
            ck_sum = checksum256(cmd_string)
            cmd_string = cmd_string+ck_sum+'#'            

            stat2 = ser.write(cmd_string)
            ack2 = ser.read(10)
            if ack2 != '$<2800!4B#': print('Problem writing command string, controller ACK =', ack2)  # $<2800!4B# == success

            stat3 = ser.close()                           # Close serial port
#
#------     Now, check status of UM506 to be sure it took the command --------
#
            ser = serial.Serial(port, 9600, timeout = 0.1)
            for i in range(0,3):
                cmd = 'SRQ'                             # Status request command
                cmd_string = '$>28001'+letr+numb+letr+numb+' '+letr+cmd+letr+cmd
                ck_sum = checksum256(cmd_string)
                cmd_string = cmd_string+ck_sum+'#'
                stat2 = ser.write(cmd_string)
                ack2 = ser.read(10)
                if ack2 != '$<2800!4B#': print('Problem writing command string, controller ACK =', ack2, 'Trying ', i, 'times.')  # $<2800!4B# == success
                if ack2 == '$<2800!4B#': break

            cmd_string = '$>2800008C#'                  # Relay response is in the TI123's buffer, this command will read it back
            stat2 = ser.write(cmd_string)
            ack2 = ser.read(150)
            stat3 = ser.close()
            temp = ack2.strip().split(' ')
            loc = str(temp).find(command)
            if loc >= 0: stat3 = True
            return(stat3)

        elif relay_model =='RF124':
            letr = relay_address[0]
            numb = relay_address[1]
            if int(relay_address[1]) <= 9:   numb = '0'+numb
            
            ser = serial.Serial(port, 9600, timeout=0.1)  # Again, set up serial port
            
            for i in range(0,3):
                cmd_string = '$>28001'+letr+numb+letr+numb+' '+letr+command+letr+command
                ck_sum = checksum256(cmd_string)
                cmd_string = cmd_string+ck_sum+'#'
                stat2 = ser.write(cmd_string)
                ack2 = ser.read(10)
                if ack2 == '$<2800!4B#': break
                if ack2 != '$<2800!4B#': print('Problem writing command string, controller ACK =', ack2, 'Trying ', i, 'times.')  # $<2800!4B# == success
                if ack2 != '$<2800!4B#': log_write(log_file, 'Problem writing command string, controller ACK =', ack2, 'Trying ', i, 'times.')

            stat3 = ser.close()                         # Close serial port
#
#           Now, check status of RF124 to be sure it took the command
#
            ser = serial.Serial(port, 9600, timeout = 0.1)
            for i in range(0,3):
                cmd = 'SRQ'                             # Status request command
                cmd_string = '$>28001'+letr+numb+letr+numb+' '+letr+cmd+letr+cmd
                ck_sum = checksum256(cmd_string)
                cmd_string = cmd_string+ck_sum+'#'
                stat2 = ser.write(cmd_string)
                ack2 = ser.read(10)
                if ack2 == '$<2800!4B#': break
                if ack2 != '$<2800!4B#': print('Problem writing command string, controller ACK =', ack2, 'Trying ', i, 'times.')  # $<2800!4B# == success
                if ack2 != '$<2800!4B#': log_write(log_file, 'Problem writing command string, controller ACK =', ack2, 'Trying ', i, 'times.')

            cmd_string = '$>2800008C#'                  # Relay response is in the TI123's buffer, this command will read it back
            stat2 = ser.write(cmd_string)
            ack2 = ser.read(150)
            stat3 = ser.close()
            temp = ack2.strip().split(' ')
            loc = str(temp).find(command)
            if loc >= 0: stat3 = True
            if loc == -1: stat3 = ack2
            return(stat3)




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