Go back to Sending and decoding OptoMMP data


To see the methods used to write these scripts, check out the earlier pages in this Getting Started with OptoMMP for Python guide.

getUptime.py

###    getUptime.py >>python getUptime.py OR >>python getUptime.py 127.0.0.1

import sys
import socket
import struct
if len(sys.argv) < 2:   # if an arguement isn't included
    host = 'localhost'  # default to localhost
else:
    host = sys.argv[1]  # otherwise use the first argument

port = 2001 # default OptoMMP port number
# create socket with IPv4 family, and TCP
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# use that socket connect to host:port tuple
s.connect((host, port))
# build uptime block request:                 F0  30  01  0C    <- uptime location in hex
myBytes = [0, 0, 4, 80,  0,  0,  255, 255,   240, 48,  1, 12,     0, 4, 0,0]

# send request and save the response
nSent = s.send(bytearray(myBytes)) # want nSent to be exactly 16 bytes
data = s.recv(24) # read response block is 24 bytes
data_block = data[16:20] # data_block is in bytes 16-19 for Read Response, stop at 20.

# decode bytearray in big-endian order (>) for integer value (i)
output = str(struct.unpack_from('>i', bytearray(data_block)))
# clip out first `(` and last two characters `,)` before printing
print 'uptime: ' + output[1:-2] + 'ms'
# close the socket:
s.close()

readModCh.py

###    readModCh.py >>python readModCh.py <module #> <channel #>
import sys
import socket
import struct

host = '127.0.0.1' # groov EPIC IP

port = 2001 # default OptoMMP port number
tcode = 5   # read block request
modN = int(sys.argv[1]) # first argument
chN = int(sys.argv[2])  # second argument

# create socket with IPv4 family, and TCP
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# use that socket connect to host:port tuple
s.connect((host, port))
# Calculate the destination offset:
# EPIC digital read start address = 0xF01E0000
dest = 0xF01E0000 + (modN * 0x1000) + (chN * 0x40)
# build the read block request:
myBytes = [0, 0, (1 << 2), (tcode << 4), 0, 0, 255, 255, int(str(hex(dest))[2:4],16), int(str(hex(dest))[4:6],16), int(str(hex(dest))[6:8],16), int(str(hex(dest))[8:10],16), 0, 16, 0, 0];

# send the read block request and save the response:
nSent = s.send(bytearray(myBytes)) # want nSent to be exactly 16 bytes
data = s.recv(24) # read block response is 24 bytes
data_block = data[16:20] # data_block is in bytes 16-19 for Read Response, stop at 20.

# decode bytearray in big-endian order (>) for integer value (i)
output = str(struct.unpack_from('>i', bytearray(data_block)))
# clip out first `(` and last two characters `,)` before printing
print 'module ' + str(modN) + ', point ' + str(chN) + ' = ' + output[1:-2]
#close the socket:
s.close()

writeModChVal.py

###    writeModChVal.py >>python writeModChVal.py <module #> <channel #> <1|0>
import sys
import socket
import struct

host = '127.0.0.1' # groov EPIC IP

port = 2001 # default OptoMMP port number
tcode = 1   # write block request
modN = int(sys.argv[1]) # first argument
chN = int(sys.argv[2])  # second argument
val = int(sys.argv[3])  # third argument

# create socket with IPv4 family, and TCP
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# use that socket connect to host:port tuple
s.connect((host, port))
# Calculate the destination offset:
# EPIC digital write start address = 0xF0220000
dest = 0xF0220000 + (modN * 0x1000) + (chN * 0x40)
# build the write block request: 
myBytes = [0, 0, (1 << 2), (tcode << 4), 0, 0, 255, 255, int(str(hex(dest))[2:4],16), int(str(hex(dest))[4:6],16), int(str(hex(dest))[6:8],16), int(str(hex(dest))[8:10],16), 0,16,  0,0,  0,0,0,val];

# send the write block request and save the response:
nSent = s.send(bytearray(myBytes)) # want nSent to be exactly 16 bytes
data = s.recv(12) # write block response is 12 bytes
data_block = data[4:8] # data_block is in bytes 4-7 for Write Response, stop at 8.

# decode bytearray in big-endian order(>) for integer value (i)
output = str(struct.unpack_from('>i', bytearray(data_block)))
# clip out first `(` and last two characters `,)` to get the status code number
status = int(output[1:-2])
if (status == 0):
    print 'Write success ' + str(status)
else:
    print 'Write failure ' + str(status)
#close the socket:
s.close()

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To see the methods used to write these scripts, check out the earlier pages in this Getting Started with OptoMMP for Python guide.

References