utils/collectd/patches/053-Add-support-for-RS485-to-modbus-plugin.patch

   1 From a00ab52931a587cf29c53a945e9295b4d7fe41ba Mon Sep 17 00:00:00 2001
   2 From: Daniel Golle <daniel@makrotopia.org>
   3 Date: Thu, 28 Mar 2019 01:52:04 +0100
   4 Subject: [PATCH] Add support for RS485 to modbus plugin
   5
   6 Allow setting up RS485 mode for Modbus-RTU
   7 ---
   8  src/collectd.conf.pod |  6 +++++
   9  src/modbus.c          | 55 +++++++++++++++++++++++++++++++++++++++----
  10  2 files changed, 57 insertions(+), 4 deletions(-)
  11
  12 --- a/src/collectd.conf.pod
  13 +++ b/src/collectd.conf.pod
  14 @@ -4234,6 +4234,12 @@ For Modbus/RTU, specifies the path to th
  15  For Modbus/RTU, specifies the baud rate of the serial device.
  16  Note, connections currently support only 8/N/1.
  17
  18 +=item B<UARTType> I<UARTType>
  19 +
  20 +For Modbus/RTU, specifies the type of the serial device.
  21 +RS232, RS422 and RS485 are supported. Defaults to RS232.
  22 +Available only on Linux systems with libmodbus>=2.9.4.
  23 +
  24  =item B<Interval> I<Interval>
  25
  26  Sets the interval (in seconds) in which the values will be collected from this
  27 --- a/src/modbus.c
  28 +++ b/src/modbus.c
  29 @@ -95,6 +95,12 @@ enum mb_conntype_e /* {{{ */
  30    MBCONN_RTU }; /* }}} */
  31  typedef enum mb_conntype_e mb_conntype_t;
  32
  33 +enum mb_uarttype_e /* {{{ */
  34 +{ UARTTYPE_RS232,
  35 +  UARTTYPE_RS422,
  36 +  UARTTYPE_RS485 }; /* }}} */
  37 +typedef enum mb_uarttype_e mb_uarttype_t;
  38 +
  39  struct mb_data_s;
  40  typedef struct mb_data_s mb_data_t;
  41  struct mb_data_s /* {{{ */
  42 @@ -124,8 +130,9 @@ struct mb_host_s /* {{{ */
  43    char host[DATA_MAX_NAME_LEN];
  44    char node[NI_MAXHOST]; /* TCP hostname or RTU serial device */
  45    /* char service[NI_MAXSERV]; */
  46 -  int port;     /* for Modbus/TCP */
  47 -  int baudrate; /* for Modbus/RTU */
  48 +  int port;               /* for Modbus/TCP */
  49 +  int baudrate;           /* for Modbus/RTU */
  50 +  mb_uarttype_t uarttype; /* UART type for Modbus/RTU */
  51    mb_conntype_t conntype;
  52    cdtime_t interval;
  53
  54 @@ -390,6 +397,22 @@ static int mb_init_connection(mb_host_t
  55      return status;
  56    }
  57
  58 +#if defined(linux) && LIBMODBUS_VERSION_CHECK(2, 9, 4)
  59 +  switch (host->uarttype) {
  60 +  case UARTTYPE_RS485:
  61 +    if (modbus_rtu_set_serial_mode(host->connection, MODBUS_RTU_RS485))
  62 +      DEBUG("Modbus plugin: Setting RS485 mode failed.");
  63 +    break;
  64 +  case UARTTYPE_RS422:
  65 +    /* libmodbus doesn't say anything about full-duplex symmetric RS422 UART */
  66 +    break;
  67 +  case UARTTYPE_RS232:
  68 +    break;
  69 +  default:
  70 +    DEBUG("Modbus plugin: Invalid UART type!.");
  71 +  }
  72 +#endif /* defined(linux) && LIBMODBUS_VERSION_CHECK(2, 9, 4) */
  73 +
  74    return 0;
  75  } /* }}} int mb_init_connection */
  76  #endif /* !LEGACY_LIBMODBUS */
  77 @@ -951,11 +974,35 @@ static int mb_config_add_host(oconfig_it
  78          status = -1;
  79      } else if (strcasecmp("Device", child->key) == 0) {
  80        status = cf_util_get_string_buffer(child, host->node, sizeof(host->node));
  81 -      if (status == 0)
  82 +      if (status == 0) {
  83          host->conntype = MBCONN_RTU;
  84 +        host->uarttype = UARTTYPE_RS232;
  85 +      }
  86      } else if (strcasecmp("Baudrate", child->key) == 0)
  87        status = cf_util_get_int(child, &host->baudrate);
  88 -    else if (strcasecmp("Interval", child->key) == 0)
  89 +    else if (strcasecmp("UARTType", child->key) == 0) {
  90 +#if defined(linux) && !LEGACY_LIBMODBUS && LIBMODBUS_VERSION_CHECK(2, 9, 4)
  91 +      char buffer[NI_MAXHOST];
  92 +      status = cf_util_get_string_buffer(child, buffer, sizeof(buffer));
  93 +      if (status != 0)
  94 +        break;
  95 +      if (strncmp(buffer, "RS485", 6) == 0)
  96 +        host->uarttype = UARTTYPE_RS485;
  97 +      else if (strncmp(buffer, "RS422", 6) == 0)
  98 +        host->uarttype = UARTTYPE_RS422;
  99 +      else if (strncmp(buffer, "RS232", 6) == 0)
 100 +        host->uarttype = UARTTYPE_RS232;
 101 +      else {
 102 +        ERROR("Modbus plugin: The UARTType \"%s\" is unknown.", buffer);
 103 +        status = -1;
 104 +        break;
 105 +      }
 106 +#else
 107 +      ERROR("Modbus plugin: Option `UARTType' not supported. Please "
 108 +            "upgrade libmodbus to at least 2.9.4");
 109 +      return -1;
 110 +#endif
 111 +    } else if (strcasecmp("Interval", child->key) == 0)
 112        status = cf_util_get_cdtime(child, &host->interval);
 113      else if (strcasecmp("Slave", child->key) == 0)
 114        /* Don't set status: Gracefully continue if a slave fails. */