src/hardware/fluke-dmm/protocol.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <config.h>
  21 #include <stdlib.h>
  22 #include <math.h>
  23 #include <string.h>
  24 #include <glib.h>
  25 #include <libsigrok/libsigrok.h>
  26 #include "libsigrok-internal.h"
  27 #include "protocol.h"
  28
  29 static int count_digits(const char *str) {
  30         int digits;
  31
  32         while (*str && *str != ' ' && *str != ',' && *str != '.')
  33                 str++;
  34
  35         digits = 0;
  36         if (*str == '.') {
  37                 str++;
  38                 while (*str && *str != ' ' && *str != ',') {
  39                         str++;
  40                         digits++;
  41                 }
  42         }
  43
  44         return digits;
  45 }
  46
  47 static void handle_qm_18x(const struct sr_dev_inst *sdi, char **tokens)
  48 {
  49         struct dev_context *devc;
  50         struct sr_datafeed_packet packet;
  51         struct sr_datafeed_analog analog;
  52         struct sr_analog_encoding encoding;
  53         struct sr_analog_meaning meaning;
  54         struct sr_analog_spec spec;
  55         float fvalue;
  56         char *e, *u;
  57         gboolean is_oor;
  58         int digits;
  59         int exponent;
  60         enum sr_mq mq;
  61         enum sr_unit unit;
  62         enum sr_mqflag mqflags;
  63
  64         devc = sdi->priv;
  65
  66         if (strcmp(tokens[0], "QM") || !tokens[1])
  67                 return;
  68
  69         if ((e = strstr(tokens[1], "Out of range"))) {
  70                 is_oor = TRUE;
  71                 fvalue = -1;
  72                 digits = 0;
  73                 while (*e && *e != '.')
  74                         e++;
  75         } else {
  76                 is_oor = FALSE;
  77                 /* Delimit the float, since sr_atof_ascii() wants only
  78                  * a valid float here. */
  79                 e = tokens[1];
  80                 while (*e && *e != ' ')
  81                         e++;
  82                 *e++ = '\0';
  83                 if (sr_atof_ascii(tokens[1], &fvalue) != SR_OK) {
  84                         /* Happens all the time, when switching modes. */
  85                         sr_dbg("Invalid float: '%s'", tokens[1]);
  86                         return;
  87                 }
  88                 digits = count_digits(tokens[1]);
  89         }
  90         while (*e && *e == ' ')
  91                 e++;
  92
  93         if (is_oor)
  94                 fvalue = NAN;
  95
  96         mq = 0;
  97         unit = 0;
  98         exponent = 0;
  99         mqflags = 0;
 100         if ((u = strstr(e, "V DC")) || (u = strstr(e, "V AC"))) {
 101                 mq = SR_MQ_VOLTAGE;
 102                 unit = SR_UNIT_VOLT;
 103                 if (!is_oor && e[0] == 'm')
 104                         exponent = -3;
 105                 /* This catches "V AC", "V DC" and "V AC+DC". */
 106                 if (strstr(u, "AC"))
 107                         mqflags |= SR_MQFLAG_AC | SR_MQFLAG_RMS;
 108                 if (strstr(u, "DC"))
 109                         mqflags |= SR_MQFLAG_DC;
 110         } else if ((u = strstr(e, "dBV")) || (u = strstr(e, "dBm"))) {
 111                 mq = SR_MQ_VOLTAGE;
 112                 if (u[2] == 'm')
 113                         unit = SR_UNIT_DECIBEL_MW;
 114                 else
 115                         unit = SR_UNIT_DECIBEL_VOLT;
 116                 mqflags |= SR_MQFLAG_AC | SR_MQFLAG_RMS;
 117         } else if ((u = strstr(e, "Ohms"))) {
 118                 mq = SR_MQ_RESISTANCE;
 119                 unit = SR_UNIT_OHM;
 120                 if (is_oor)
 121                         fvalue = INFINITY;
 122                 else if (e[0] == 'k')
 123                         exponent = 3;
 124                 else if (e[0] == 'M')
 125                         exponent = 6;
 126         } else if (!strcmp(e, "nS")) {
 127                 mq = SR_MQ_CONDUCTANCE;
 128                 unit = SR_UNIT_SIEMENS;
 129                 exponent = -9;
 130         } else if ((u = strstr(e, "Farads"))) {
 131                 mq = SR_MQ_CAPACITANCE;
 132                 unit = SR_UNIT_FARAD;
 133                 if (!is_oor) {
 134                         if (e[0] == 'm')
 135                                 exponent = -3;
 136                         else if (e[0] == 'u')
 137                                 exponent = -6;
 138                         else if (e[0] == 'n')
 139                                 exponent = -9;
 140                 }
 141         } else if ((u = strstr(e, "Deg C")) || (u = strstr(e, "Deg F"))) {
 142                 mq = SR_MQ_TEMPERATURE;
 143                 if (u[4] == 'C')
 144                         unit = SR_UNIT_CELSIUS;
 145                 else
 146                         unit = SR_UNIT_FAHRENHEIT;
 147         } else if ((u = strstr(e, "A AC")) || (u = strstr(e, "A DC"))) {
 148                 mq = SR_MQ_CURRENT;
 149                 unit = SR_UNIT_AMPERE;
 150                 /* This catches "A AC", "A DC" and "A AC+DC". */
 151                 if (strstr(u, "AC"))
 152                         mqflags |= SR_MQFLAG_AC | SR_MQFLAG_RMS;
 153                 if (strstr(u, "DC"))
 154                         mqflags |= SR_MQFLAG_DC;
 155                 if (!is_oor) {
 156                         if (e[0] == 'm')
 157                                 exponent = -3;
 158                         else if (e[0] == 'u')
 159                                 exponent = -6;
 160                 }
 161         } else if ((u = strstr(e, "Hz"))) {
 162                 mq = SR_MQ_FREQUENCY;
 163                 unit = SR_UNIT_HERTZ;
 164                 if (e[0] == 'k')
 165                         exponent = 3;
 166         } else if (!strcmp(e, "%")) {
 167                 mq = SR_MQ_DUTY_CYCLE;
 168                 unit = SR_UNIT_PERCENTAGE;
 169         } else if ((u = strstr(e, "ms"))) {
 170                 mq = SR_MQ_PULSE_WIDTH;
 171                 unit = SR_UNIT_SECOND;
 172                 exponent = -3;
 173         }
 174
 175         if (mq != 0) {
 176                 /* Got a measurement. */
 177                 digits -= exponent;
 178                 fvalue *= pow(10.0f, exponent);
 179
 180                 sr_analog_init(&analog, &encoding, &meaning, &spec, digits);
 181                 analog.data = &fvalue;
 182                 analog.num_samples = 1;
 183                 analog.meaning->unit = unit;
 184                 analog.meaning->mq = mq;
 185                 analog.meaning->mqflags = mqflags;
 186                 analog.meaning->channels = sdi->channels;
 187
 188                 packet.type = SR_DF_ANALOG;
 189                 packet.payload = &analog;
 190                 sr_session_send(sdi, &packet);
 191                 sr_sw_limits_update_samples_read(&devc->limits, 1);
 192         }
 193 }
 194
 195 static void handle_qm_28x(const struct sr_dev_inst *sdi, char **tokens)
 196 {
 197         struct dev_context *devc;
 198         struct sr_datafeed_packet packet;
 199         struct sr_datafeed_analog analog;
 200         struct sr_analog_encoding encoding;
 201         struct sr_analog_meaning meaning;
 202         struct sr_analog_spec spec;
 203         float fvalue;
 204         int digits;
 205
 206         devc = sdi->priv;
 207
 208         if (!tokens[1])
 209                 return;
 210
 211         if (sr_atof_ascii(tokens[0], &fvalue) != SR_OK) {
 212                 sr_err("Invalid float '%s'.", tokens[0]);
 213                 return;
 214         }
 215         digits = count_digits(tokens[0]);
 216
 217         sr_analog_init(&analog, &encoding, &meaning, &spec, digits);
 218         analog.data = &fvalue;
 219         analog.meaning->channels = sdi->channels;
 220         analog.num_samples = 1;
 221         analog.meaning->mq = 0;
 222
 223         if (!strcmp(tokens[1], "VAC") || !strcmp(tokens[1], "VDC")) {
 224                 analog.meaning->mq = SR_MQ_VOLTAGE;
 225                 analog.meaning->unit = SR_UNIT_VOLT;
 226                 if (!strcmp(tokens[2], "NORMAL")) {
 227                         if (tokens[1][1] == 'A') {
 228                                 analog.meaning->mqflags |= SR_MQFLAG_AC;
 229                                 analog.meaning->mqflags |= SR_MQFLAG_RMS;
 230                         } else
 231                                 analog.meaning->mqflags |= SR_MQFLAG_DC;
 232                 } else if (!strcmp(tokens[2], "OL") || !strcmp(tokens[2], "OL_MINUS")) {
 233                         fvalue = NAN;
 234                 } else
 235                         analog.meaning->mq = 0;
 236         } else if (!strcmp(tokens[1], "dBV") || !strcmp(tokens[1], "dBm")) {
 237                 analog.meaning->mq = SR_MQ_VOLTAGE;
 238                 if (tokens[1][2] == 'm')
 239                         analog.meaning->unit = SR_UNIT_DECIBEL_MW;
 240                 else
 241                         analog.meaning->unit = SR_UNIT_DECIBEL_VOLT;
 242                 analog.meaning->mqflags |= SR_MQFLAG_AC | SR_MQFLAG_RMS;
 243         } else if (!strcmp(tokens[1], "CEL") || !strcmp(tokens[1], "FAR")) {
 244                 if (!strcmp(tokens[2], "NORMAL")) {
 245                         analog.meaning->mq = SR_MQ_TEMPERATURE;
 246                         if (tokens[1][0] == 'C')
 247                                 analog.meaning->unit = SR_UNIT_CELSIUS;
 248                         else
 249                                 analog.meaning->unit = SR_UNIT_FAHRENHEIT;
 250                 }
 251         } else if (!strcmp(tokens[1], "OHM")) {
 252                 if (!strcmp(tokens[3], "NONE")) {
 253                         analog.meaning->mq = SR_MQ_RESISTANCE;
 254                         analog.meaning->unit = SR_UNIT_OHM;
 255                         if (!strcmp(tokens[2], "OL") || !strcmp(tokens[2], "OL_MINUS")) {
 256                                 fvalue = INFINITY;
 257                         } else if (strcmp(tokens[2], "NORMAL"))
 258                                 analog.meaning->mq = 0;
 259                 } else if (!strcmp(tokens[3], "OPEN_CIRCUIT")) {
 260                         analog.meaning->mq = SR_MQ_CONTINUITY;
 261                         analog.meaning->unit = SR_UNIT_BOOLEAN;
 262                         fvalue = 0.0;
 263                 } else if (!strcmp(tokens[3], "SHORT_CIRCUIT")) {
 264                         analog.meaning->mq = SR_MQ_CONTINUITY;
 265                         analog.meaning->unit = SR_UNIT_BOOLEAN;
 266                         fvalue = 1.0;
 267                 }
 268         } else if (!strcmp(tokens[1], "F")
 269                         && !strcmp(tokens[2], "NORMAL")
 270                         && !strcmp(tokens[3], "NONE")) {
 271                 analog.meaning->mq = SR_MQ_CAPACITANCE;
 272                 analog.meaning->unit = SR_UNIT_FARAD;
 273         } else if (!strcmp(tokens[1], "AAC") || !strcmp(tokens[1], "ADC")) {
 274                 analog.meaning->mq = SR_MQ_CURRENT;
 275                 analog.meaning->unit = SR_UNIT_AMPERE;
 276                 if (!strcmp(tokens[2], "NORMAL")) {
 277                         if (tokens[1][1] == 'A') {
 278                                 analog.meaning->mqflags |= SR_MQFLAG_AC;
 279                                 analog.meaning->mqflags |= SR_MQFLAG_RMS;
 280                         } else
 281                                 analog.meaning->mqflags |= SR_MQFLAG_DC;
 282                 } else if (!strcmp(tokens[2], "OL") || !strcmp(tokens[2], "OL_MINUS")) {
 283                         fvalue = NAN;
 284                 } else
 285                         analog.meaning->mq = 0;
 286         } else if (!strcmp(tokens[1], "Hz") && !strcmp(tokens[2], "NORMAL")) {
 287                 analog.meaning->mq = SR_MQ_FREQUENCY;
 288                 analog.meaning->unit = SR_UNIT_HERTZ;
 289         } else if (!strcmp(tokens[1], "PCT") && !strcmp(tokens[2], "NORMAL")) {
 290                 analog.meaning->mq = SR_MQ_DUTY_CYCLE;
 291                 analog.meaning->unit = SR_UNIT_PERCENTAGE;
 292         } else if (!strcmp(tokens[1], "S") && !strcmp(tokens[2], "NORMAL")) {
 293                 analog.meaning->mq = SR_MQ_PULSE_WIDTH;
 294                 analog.meaning->unit = SR_UNIT_SECOND;
 295         } else if (!strcmp(tokens[1], "SIE") && !strcmp(tokens[2], "NORMAL")) {
 296                 analog.meaning->mq = SR_MQ_CONDUCTANCE;
 297                 analog.meaning->unit = SR_UNIT_SIEMENS;
 298         }
 299
 300         if (analog.meaning->mq != 0) {
 301                 /* Got a measurement. */
 302                 packet.type = SR_DF_ANALOG;
 303                 packet.payload = &analog;
 304                 sr_session_send(sdi, &packet);
 305                 sr_sw_limits_update_samples_read(&devc->limits, 1);
 306         }
 307 }
 308
 309 static void handle_qm_19x_meta(const struct sr_dev_inst *sdi, char **tokens)
 310 {
 311         struct dev_context *devc;
 312         int meas_type, meas_unit, meas_char, i;
 313
 314         /* Make sure we have 7 valid tokens. */
 315         for (i = 0; tokens[i] && i < 7; i++);
 316         if (i != 7)
 317                 return;
 318
 319         if (strcmp(tokens[1], "1"))
 320                 /* Invalid measurement. */
 321                 return;
 322
 323         if (strcmp(tokens[2], "3"))
 324                 /* Only interested in input from the meter mode source. */
 325                 return;
 326
 327         devc = sdi->priv;
 328
 329         /* Measurement type 11 == absolute, 19 = relative */
 330         meas_type = strtol(tokens[0], NULL, 10);
 331         if (meas_type != 11 && meas_type != 19)
 332                 /* Device is in some mode we don't support. */
 333                 return;
 334
 335         /* We might get metadata for absolute and relative mode (if the device
 336          * is in relative mode). In that case, relative takes precedence. */
 337         if (meas_type == 11 && devc->meas_type == 19)
 338                 return;
 339
 340         meas_unit = strtol(tokens[3], NULL, 10);
 341         if (meas_unit == 0)
 342                 /* Device is turned off. Really. */
 343                 return;
 344         meas_char = strtol(tokens[4], NULL, 10);
 345
 346         devc->mq = 0;
 347         devc->unit = 0;
 348         devc->mqflags = 0;
 349
 350         switch (meas_unit) {
 351         case 1:
 352                 devc->mq = SR_MQ_VOLTAGE;
 353                 devc->unit = SR_UNIT_VOLT;
 354                 if (meas_char == 1)
 355                         devc->mqflags |= SR_MQFLAG_DC;
 356                 else if (meas_char == 2)
 357                         devc->mqflags |= SR_MQFLAG_AC;
 358                 else if (meas_char == 3)
 359                         devc->mqflags |= SR_MQFLAG_DC | SR_MQFLAG_AC;
 360                 else if (meas_char == 15)
 361                         devc->mqflags |= SR_MQFLAG_DIODE | SR_MQFLAG_DC;
 362                 break;
 363         case 2:
 364                 devc->mq = SR_MQ_CURRENT;
 365                 devc->unit = SR_UNIT_AMPERE;
 366                 if (meas_char == 1)
 367                         devc->mqflags |= SR_MQFLAG_DC;
 368                 else if (meas_char == 2)
 369                         devc->mqflags |= SR_MQFLAG_AC;
 370                 else if (meas_char == 3)
 371                         devc->mqflags |= SR_MQFLAG_DC | SR_MQFLAG_AC;
 372                 break;
 373         case 3:
 374                 if (meas_char == 1) {
 375                         devc->mq = SR_MQ_RESISTANCE;
 376                         devc->unit = SR_UNIT_OHM;
 377                 } else if (meas_char == 16) {
 378                         devc->mq = SR_MQ_CONTINUITY;
 379                         devc->unit = SR_UNIT_BOOLEAN;
 380                 }
 381                 break;
 382         case 12:
 383                 devc->mq = SR_MQ_TEMPERATURE;
 384                 devc->unit = SR_UNIT_CELSIUS;
 385                 break;
 386         case 13:
 387                 devc->mq = SR_MQ_TEMPERATURE;
 388                 devc->unit = SR_UNIT_FAHRENHEIT;
 389                 break;
 390         default:
 391                 sr_dbg("unknown unit: %d", meas_unit);
 392         }
 393         if (devc->mq == 0 && devc->unit == 0)
 394                 return;
 395
 396         /* If we got here, we know how to interpret the measurement. */
 397         devc->meas_type = meas_type;
 398         if (meas_type == 11)
 399                 /* Absolute meter reading. */
 400                 devc->is_relative = FALSE;
 401         else if (!strcmp(tokens[0], "19"))
 402                 /* Relative meter reading. */
 403                 devc->is_relative = TRUE;
 404
 405 }
 406
 407 static void handle_qm_19x_data(const struct sr_dev_inst *sdi, char **tokens)
 408 {
 409         struct dev_context *devc;
 410         struct sr_datafeed_packet packet;
 411         struct sr_datafeed_analog analog;
 412         struct sr_analog_encoding encoding;
 413         struct sr_analog_meaning meaning;
 414         struct sr_analog_spec spec;
 415         float fvalue;
 416         int digits;
 417
 418         digits = 2;
 419         if (!strcmp(tokens[0], "9.9E+37")) {
 420                 /* An invalid measurement shows up on the display as "OL", but
 421                  * comes through like this. Since comparing 38-digit floats
 422                  * is rather problematic, we'll cut through this here. */
 423                 fvalue = NAN;
 424         } else {
 425                 if (sr_atof_ascii(tokens[0], &fvalue) != SR_OK || fvalue == 0.0) {
 426                         sr_err("Invalid float '%s'.", tokens[0]);
 427                         return;
 428                 }
 429                 digits = count_digits(tokens[0]);
 430         }
 431
 432         devc = sdi->priv;
 433         if (devc->mq == 0 || devc->unit == 0)
 434                 /* Don't have valid metadata yet. */
 435                 return;
 436
 437         if (devc->mq == SR_MQ_RESISTANCE && isnan(fvalue))
 438                 fvalue = INFINITY;
 439         else if (devc->mq == SR_MQ_CONTINUITY) {
 440                 if (isnan(fvalue))
 441                         fvalue = 0.0;
 442                 else
 443                         fvalue = 1.0;
 444         }
 445
 446         sr_analog_init(&analog, &encoding, &meaning, &spec, digits);
 447         analog.meaning->channels = sdi->channels;
 448         analog.num_samples = 1;
 449         analog.data = &fvalue;
 450         analog.meaning->mq = devc->mq;
 451         analog.meaning->unit = devc->unit;
 452         analog.meaning->mqflags = 0;
 453         packet.type = SR_DF_ANALOG;
 454         packet.payload = &analog;
 455         sr_session_send(sdi, &packet);
 456
 457         sr_sw_limits_update_samples_read(&devc->limits, 1);
 458 }
 459
 460 static void handle_line(const struct sr_dev_inst *sdi)
 461 {
 462         struct dev_context *devc;
 463         struct sr_serial_dev_inst *serial;
 464         int num_tokens, n, i;
 465         char cmd[16], **tokens;
 466         int ret;
 467
 468         devc = sdi->priv;
 469         serial = sdi->conn;
 470         sr_spew("Received line '%s' (%d).", devc->buf, devc->buflen);
 471
 472         if (devc->buflen == 1) {
 473                 if (devc->buf[0] != '0') {
 474                         /* Not just a CMD_ACK from the query command. */
 475                         sr_dbg("Got CMD_ACK '%c'.", devc->buf[0]);
 476                         devc->expect_response = FALSE;
 477                 }
 478                 devc->buflen = 0;
 479                 return;
 480         }
 481
 482         tokens = g_strsplit(devc->buf, ",", 0);
 483         if (tokens[0]) {
 484                 switch (devc->profile->model) {
 485                 case FLUKE_87:
 486                 case FLUKE_89:
 487                 case FLUKE_187:
 488                 case FLUKE_189:
 489                         devc->expect_response = FALSE;
 490                         handle_qm_18x(sdi, tokens);
 491                         break;
 492                 case FLUKE_190:
 493                         devc->expect_response = FALSE;
 494                         num_tokens = g_strv_length(tokens);
 495                         if (num_tokens < 7) {
 496                                 /* Response to QM <n> measurement request. */
 497                                 handle_qm_19x_data(sdi, tokens);
 498                                 break;
 499                         }
 500                         /*
 501                          * Response to QM: This is a comma-separated list of
 502                          * fields with metadata about the measurement. This
 503                          * format can return multiple sets of metadata,
 504                          * split into sets of 7 tokens each.
 505                          */
 506                         devc->meas_type = 0;
 507                         for (i = 0; i < num_tokens; i += 7)
 508                                 handle_qm_19x_meta(sdi, tokens + i);
 509                         if (devc->meas_type) {
 510                                 /*
 511                                  * Slip the request in now, before the main
 512                                  * timer loop asks for metadata again.
 513                                  */
 514                                 n = sprintf(cmd, "QM %d\r", devc->meas_type);
 515                                 ret = serial_write_blocking(serial,
 516                                         cmd, n, SERIAL_WRITE_TIMEOUT_MS);
 517                                 if (ret < 0)
 518                                         sr_err("Cannot send QM (measurement).");
 519                         }
 520                         break;
 521                 case FLUKE_287:
 522                 case FLUKE_289:
 523                         devc->expect_response = FALSE;
 524                         handle_qm_28x(sdi, tokens);
 525                         break;
 526                 }
 527         }
 528         g_strfreev(tokens);
 529         devc->buflen = 0;
 530 }
 531
 532 SR_PRIV int fluke_receive_data(int fd, int revents, void *cb_data)
 533 {
 534         struct sr_dev_inst *sdi;
 535         struct dev_context *devc;
 536         struct sr_serial_dev_inst *serial;
 537         int len;
 538         int64_t now, elapsed;
 539
 540         (void)fd;
 541
 542         if (!(sdi = cb_data))
 543                 return TRUE;
 544
 545         if (!(devc = sdi->priv))
 546                 return TRUE;
 547
 548         serial = sdi->conn;
 549         if (revents == G_IO_IN) {
 550                 /* Serial data arrived. */
 551                 while (FLUKEDMM_BUFSIZE - devc->buflen - 1 > 0) {
 552                         len = serial_read_nonblocking(serial, devc->buf + devc->buflen, 1);
 553                         if (len < 1)
 554                                 break;
 555                         devc->buflen++;
 556                         *(devc->buf + devc->buflen) = '\0';
 557                         if (*(devc->buf + devc->buflen - 1) == '\r') {
 558                                 *(devc->buf + --devc->buflen) = '\0';
 559                                 handle_line(sdi);
 560                                 break;
 561                         }
 562                 }
 563         }
 564
 565         if (sr_sw_limits_check(&devc->limits)) {
 566                 sr_dev_acquisition_stop(sdi);
 567                 return TRUE;
 568         }
 569
 570         now = g_get_monotonic_time() / 1000;
 571         elapsed = now - devc->cmd_sent_at;
 572         /* Send query command at poll_period interval, or after 1 second
 573          * has elapsed. This will make it easier to recover from any
 574          * out-of-sync or temporary disconnect issues. */
 575         if ((devc->expect_response == FALSE && elapsed > devc->profile->poll_period)
 576                         || elapsed > devc->profile->timeout) {
 577                 if (serial_write_blocking(serial, "QM\r", 3, SERIAL_WRITE_TIMEOUT_MS) < 0)
 578                         sr_err("Unable to send QM.");
 579                 devc->cmd_sent_at = now;
 580                 devc->expect_response = TRUE;
 581         }
 582
 583         return TRUE;
 584 }