Merge pull request #2729 from cekstam/add-scale-and-shift-to-modbus

diff --git a/src/collectd.conf.in b/src/collectd.conf.in
index 30791bd..662b483 100644 (file)
--- a/src/collectd.conf.in
+++ b/src/collectd.conf.in
@@ -834,6 +834,8 @@
 #              RegisterType float
 #              Type gauge
 #              Instance "..."
+#              #Scale 1.0
+#              #Shift 0.0
 #      </Data>
 #
 #      <Host "name">

diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index 36794cd..7a21ba2 100644 (file)
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -4242,8 +4242,9 @@ which the sizes of physical memory vary.
 
 The B<modbus plugin> connects to a Modbus "slave" via Modbus/TCP or Modbus/RTU and
 reads register values. It supports reading single registers (unsigned 16E<nbsp>bit
-values), large integer values (unsigned 32E<nbsp>bit values) and floating point
-values (two registers interpreted as IEEE floats in big endian notation).
+values), large integer values (unsigned 32E<nbsp>bit and 64E<nbsp>bit values) and
+floating point values (two registers interpreted as IEEE floats in big endian
+notation).
 
 B<Synopsis:>
 
@@ -4253,6 +4254,8 @@ B<Synopsis:>
    RegisterCmd ReadHolding
    Type voltage
    Instance "input-1"
+   #Scale 1.0
+   #Shift 0.0
  </Data>
 
  <Data "voltage-input-2">
@@ -4341,9 +4344,19 @@ supported.
 
 =item B<Instance> I<Instance>
 
-Sets the type instance to use when dispatching the value to I<collectd>. If
+Sets the type instance to use when dispatching the value to I<Instance>. If
 unset, an empty string (no type instance) is used.
 
+=item B<Scale> I<Value>
+
+The values taken from device are multiplied by I<Value>. The field is optional
+and the default is B<1.0>.
+
+=item B<Shift> I<Value>
+
+I<Value> is added to values from device after they have been multiplied by
+B<Scale> value. The field is optional and the default value is B<0.0>.
+
 =back
 
 =item E<lt>B<Host> I<Name>E<gt> blocks

diff --git a/src/modbus.c b/src/modbus.c
index 40e0079..bb9eaa0 100644 (file)
--- a/src/modbus.c
+++ b/src/modbus.c
@@ -107,6 +107,8 @@ struct mb_data_s /* {{{ */
   mb_mreg_type_t modbus_register_type;
   char type[DATA_MAX_NAME_LEN];
   char instance[DATA_MAX_NAME_LEN];
+  double scale;
+  double shift;
 
   mb_data_t *next;
 }; /* }}} */
@@ -394,16 +396,16 @@ static int mb_init_connection(mb_host_t *host) /* {{{ */
 } /* }}} int mb_init_connection */
 #endif /* !LEGACY_LIBMODBUS */
 
-#define CAST_TO_VALUE_T(ds, vt, raw)                                           \
+#define CAST_TO_VALUE_T(ds, vt, raw, scale, shift)                             \
   do {                                                                         \
     if ((ds)->ds[0].type == DS_TYPE_COUNTER)                                   \
-      (vt).counter = (counter_t)(raw);                                         \
+      (vt).counter = (((counter_t)(raw)*scale) + shift);                       \
     else if ((ds)->ds[0].type == DS_TYPE_GAUGE)                                \
-      (vt).gauge = (gauge_t)(raw);                                             \
+      (vt).gauge = (((gauge_t)(raw)*scale) + shift);                           \
     else if ((ds)->ds[0].type == DS_TYPE_DERIVE)                               \
-      (vt).derive = (derive_t)(raw);                                           \
+      (vt).derive = (((derive_t)(raw)*scale) + shift);                         \
     else /* if (ds->ds[0].type == DS_TYPE_ABSOLUTE) */                         \
-      (vt).absolute = (absolute_t)(raw);                                       \
+      (vt).absolute = (((absolute_t)(raw)*scale) + shift);                     \
   } while (0)
 
 static int mb_read_data(mb_host_t *host, mb_slave_t *slave, /* {{{ */
@@ -537,7 +539,7 @@ static int mb_read_data(mb_host_t *host, mb_slave_t *slave, /* {{{ */
           "Returned float value is %g",
           (double)float_value);
 
-    CAST_TO_VALUE_T(ds, vt, float_value);
+    CAST_TO_VALUE_T(ds, vt, float_value, data->scale, data->shift);
     mb_submit(host, slave, data, vt);
   } else if (data->register_type == REG_TYPE_FLOAT_CDAB) {
     float float_value;
@@ -548,7 +550,7 @@ static int mb_read_data(mb_host_t *host, mb_slave_t *slave, /* {{{ */
           "Returned float value is %g",
           (double)float_value);
 
-    CAST_TO_VALUE_T(ds, vt, float_value);
+    CAST_TO_VALUE_T(ds, vt, float_value, data->scale, data->shift);
     mb_submit(host, slave, data, vt);
   } else if (data->register_type == REG_TYPE_INT32) {
     union {
@@ -562,7 +564,7 @@ static int mb_read_data(mb_host_t *host, mb_slave_t *slave, /* {{{ */
           "Returned int32 value is %" PRIi32,
           v.i32);
 
-    CAST_TO_VALUE_T(ds, vt, v.i32);
+    CAST_TO_VALUE_T(ds, vt, v.i32, data->scale, data->shift);
     mb_submit(host, slave, data, vt);
   } else if (data->register_type == REG_TYPE_INT32_CDAB) {
     union {
@@ -576,7 +578,7 @@ static int mb_read_data(mb_host_t *host, mb_slave_t *slave, /* {{{ */
           "Returned int32 value is %" PRIi32,
           v.i32);
 
-    CAST_TO_VALUE_T(ds, vt, v.i32);
+    CAST_TO_VALUE_T(ds, vt, v.i32, data->scale, data->shift);
     mb_submit(host, slave, data, vt);
   } else if (data->register_type == REG_TYPE_INT16) {
     union {
@@ -591,7 +593,7 @@ static int mb_read_data(mb_host_t *host, mb_slave_t *slave, /* {{{ */
           "Returned int16 value is %" PRIi16,
           v.i16);
 
-    CAST_TO_VALUE_T(ds, vt, v.i16);
+    CAST_TO_VALUE_T(ds, vt, v.i16, data->scale, data->shift);
     mb_submit(host, slave, data, vt);
   } else if (data->register_type == REG_TYPE_UINT32) {
     uint32_t v32;
@@ -602,7 +604,7 @@ static int mb_read_data(mb_host_t *host, mb_slave_t *slave, /* {{{ */
           "Returned uint32 value is %" PRIu32,
           v32);
 
-    CAST_TO_VALUE_T(ds, vt, v32);
+    CAST_TO_VALUE_T(ds, vt, v32, data->scale, data->shift);
     mb_submit(host, slave, data, vt);
   } else if (data->register_type == REG_TYPE_UINT32_CDAB) {
     uint32_t v32;
@@ -613,7 +615,7 @@ static int mb_read_data(mb_host_t *host, mb_slave_t *slave, /* {{{ */
           "Returned uint32 value is %" PRIu32,
           v32);
 
-    CAST_TO_VALUE_T(ds, vt, v32);
+    CAST_TO_VALUE_T(ds, vt, v32, data->scale, data->shift);
     mb_submit(host, slave, data, vt);
   } else if (data->register_type == REG_TYPE_UINT64) {
     uint64_t v64;
@@ -625,7 +627,7 @@ static int mb_read_data(mb_host_t *host, mb_slave_t *slave, /* {{{ */
           "Returned uint64 value is %" PRIu64,
           v64);
 
-    CAST_TO_VALUE_T(ds, vt, v64);
+    CAST_TO_VALUE_T(ds, vt, v64, data->scale, data->shift);
     mb_submit(host, slave, data, vt);
   } else if (data->register_type == REG_TYPE_INT64) {
     union {
@@ -640,7 +642,7 @@ static int mb_read_data(mb_host_t *host, mb_slave_t *slave, /* {{{ */
           "Returned uint64 value is %" PRIi64,
           v.i64);
 
-    CAST_TO_VALUE_T(ds, vt, v.i64);
+    CAST_TO_VALUE_T(ds, vt, v.i64, data->scale, data->shift);
     mb_submit(host, slave, data, vt);
   } else /* if (data->register_type == REG_TYPE_UINT16) */
   {
@@ -650,7 +652,7 @@ static int mb_read_data(mb_host_t *host, mb_slave_t *slave, /* {{{ */
           "Returned uint16 value is %" PRIu16,
           values[0]);
 
-    CAST_TO_VALUE_T(ds, vt, values[0]);
+    CAST_TO_VALUE_T(ds, vt, values[0], data->scale, data->shift);
     mb_submit(host, slave, data, vt);
   }
 
@@ -757,6 +759,8 @@ static int mb_config_add_data(oconfig_item_t *ci) /* {{{ */
   data.name = NULL;
   data.register_type = REG_TYPE_UINT16;
   data.next = NULL;
+  data.scale = 1;
+  data.shift = 0;
 
   status = cf_util_get_string(ci, &data.name);
   if (status != 0)
@@ -770,6 +774,10 @@ static int mb_config_add_data(oconfig_item_t *ci) /* {{{ */
     else if (strcasecmp("Instance", child->key) == 0)
       status = cf_util_get_string_buffer(child, data.instance,
                                          sizeof(data.instance));
+    else if (strcasecmp("Scale", child->key) == 0)
+      status = cf_util_get_double(child, &data.scale);
+    else if (strcasecmp("Shift", child->key) == 0)
+      status = cf_util_get_double(child, &data.shift);
     else if (strcasecmp("RegisterBase", child->key) == 0)
       status = cf_util_get_int(child, &data.register_base);
     else if (strcasecmp("RegisterType", child->key) == 0) {