Dicon GP700 GPIB Scanning script for I-matrix

gp700.py

#!/usr/bin/env python3
import pyvisa
import subprocess
import re
import time


def optical_data(iface):
    # no json support in ethtool for eeprom dump yet :(
    for _ in range(10):
        try:
            odraw = subprocess.check_output(['sudo', '/home/bluecmd/ethtool/ethtool', '-m', iface]).decode()
        except subprocess.CalledProcessError:
            # retry if netlink is acting up
            time.sleep(0.1)
            continue

    od = [[y.strip() for y in x.split(':', maxsplit=1)] for x in odraw.strip().split('\n')]
    rcvr_dbm = []
    xmit_dbm = []
    for key, value in od:
        g = re.search(r'\/ ([-0-9.]+) dBm', value)
        if key.startswith('Rcvr signal avg optical power'):
            rcvr_dbm.append(float(g.group(1)) if g else -40.0)
        elif key.startswith('Transmit avg optical power'):
            xmit_dbm.append(float(g.group(1)) if g else -40.0)
    return round(sum(xmit_dbm)/len(xmit_dbm), 2), round(sum(rcvr_dbm)/len(rcvr_dbm), 2)


def generate_paths(src, dst, loop_list):
    # loopback
    yield 'Loopback', ((src, dst),)
    # 1 hop
    for port in loop_list:
        yield f'Via {port}', ((src, port), (port, dst))
    # 2 hop
    for port1 in loop_list:
        for port2 in loop_list:
            if port2 == port1:
                continue
            yield f'Via {port1} -> {port2}', ((src, port1), (port1, port2), (port2, dst))
    # 3 hop
    for port1 in loop_list:
        for port2 in loop_list:
            if port2 == port1:
                continue
            for port3 in loop_list:
                if port3 == port2 or port3 == port1:
                    continue
                yield f'Via {port1} -> {port2} -> {port3}', ((src, port1), (port1, port2), (port2, port3), (port3, dst))


if __name__ == '__main__':
    rm = pyvisa.ResourceManager()
    gp700 = rm.open_resource('GPIB0::30::INSTR')

    id_mf, id_model, id_serial, id_fw = [x.strip() for x in gp700.query('*IDN?').strip().split(',')]
    if id_mf != 'DiCon Fiberoptics Inc' or id_model != 'GP700':
        raise Exception(f'Unsupported device: {id_mf}, {id_model}')
    print(f' [*] Connected to {id_model}')

    loop_list = range(4, 16)

    for src, dst, iface in ((1, 1, 'ens1f0'), (2, 2, 'ens1f1')):
        with open(f'{iface}.{int(time.time())}.results', 'w') as res:
            print(f' [*] Starting scan session for {iface}')
            for descr, path in generate_paths(src, dst, loop_list=loop_list):
                for port, sel in path:
                    gp700.write(f'I{port} {sel}')
                    time.sleep(0.1)
                time.sleep(2)
                xmit, rcv = optical_data(iface)
                loss_dbm = rcv - xmit
                print(' [*] Scenario:', descr, '=> {0:0.2f} dBm'.format(loss_dbm))
                res.write(','.join((str(x[0]) for x in path)) + ' {0:0.2f}'.format(loss_dbm) + '\n')
                res.flush()