Changes

<span style="color:red"> <b>Note: </b></span>MQTT Gateway uses <i>Register Number</i> instead of <i>Register Address</i> for pointing to a register. For example, to request the <i>Uptime</i> of a device, you must use <b>2</b> in the <i>Register Number</i> field.

<span style="color:red"> <b>Note: </b></span>MQTT Gateway uses <i>Register Number</i> instead of <i>Register Address</i> for pointing to a register. For example, to request the <i>Uptime</i> of a device, you must use <b>2</b> in the <i>Register Number</i> field.

Modbus request data sent in the MQTT payload should be generated in accordance with the following format:

Modbus request data sent in the MQTT payload should be generated in accordance with the one of the following formats:

<b>0 <COOKIE> <IP_TYPE> <IP> <PORT> <TIMEOUT> <SLAVE_ID> <MODBUS_FUNCTION> <REGISTER_NUMBER> <REGISTER_COUNT/VALUE></b>

  <b>0 <COOKIE> <IP_TYPE> <IP> <PORT> <TIMEOUT> <SLAVE_ID> <MODBUS_FUNCTION> <FIRST_REGISTER> <REGISTER_COUNT/VALUES></b>

  <b>2 <COOKIE> <CONNECTION_INDEX> 0 <IP_TYPE> <IP> <PORT> <TIMEOUT></b>

Explanation:

Explanation:

<ul>

<ul>

     <li><b>Cookie</b> - a 64-bit unsigned integer in range [0..2⁶⁴-1]). A cookie is used in order to distinguish which response belongs to which request, each request and the corresponding response contain a matching cookie: a 64-bit unsigned integer.</li>

     <li><b>Cookie</b> - a 64-bit unsigned integer in range [0..2⁶⁴]). A cookie is used in order to distinguish which response belongs to which request, each request and the corresponding response contain a matching cookie: a 64-bit unsigned integer.</li>

     <li><b>IP type</b> - host IP address type. Possible values:

     <li><b>IP type</b> - host IP address type. Possible values:

         <ul>

         <ul>

             <li><b>1</b> - IPv6 address;</li>

             <li><b>1</b> - IPv6 address;</li>

             <li><b>2</b> - hostname that will be resolved to an IP address.</li>

             <li><b>2</b> - hostname that will be resolved to an IP address.</li>

         </ul></li>

         </ul>

    </li>

     <li><b>IP</b> - IP address of a Modbus TCP slave. IPv6 must be presented in full form (e.g., <i>2001:0db8:0000:0000:0000:8a2e:0370:7334</i>).</li>

     <li><b>IP</b> - IP address of a Modbus TCP slave. IPv6 must be presented in full form (e.g., <i>2001:0db8:0000:0000:0000:8a2e:0370:7334</i>).</li>

     <li><b>Port</b> - port number of the Modbus TCP slave.</li>

     <li><b>Port</b> - port number of the Modbus TCP slave.</li>

     <li><b>Timeout</b> - timeout for Modbus TCP connection, in seconds. Range [1..999].</li>

     <li><b>Timeout</b> - timeout for Modbus connection, in seconds. Range [1..999].</li>

     <li><b>Slave ID</b> - Modbus TCP slave ID. Range [1..255].</li>

     <li><b>Slave ID</b> - Modbus TCP slave ID. Range [1..255].</li>

     <li><b>Modbus function</b> - Modbus task type that will be executed. Possible values are:

     <li><b>Modbus function</b> - Modbus task type that will be executed. Possible values are:

         <ul>

         <ul>

             <li><b>3</b> - read holding registers;</li>

             <li><b>3</b> - read holding registers;</li>

             <li><b>6</b> - write to a single holding register;</li>

             <li><b>6</b> - write to a single holding register;</li>

             <li><b>16</b> - write to multiple holding registers.</li>

             <li><b>16</b> - write to multiple holding registers.</li>

         </ul></li>

         </ul>

     <li><b>Register number</b> - number (not address) of the first register (in range [1..65536]) from which the registers will be read/written to.

    </li>

     <li><b>First register</b> - number (not address) of the first register/coil/input (in range [1..65536]) from which the registers/coils/inputs will be read/written to.</li>

     <li><b>Register count/value</b> - this value depends on the Modbus function:

     <li><b>Register count/value</b> - this value depends on the Modbus function:

         <ul>

         <ul>

             <li><b>3</b> - <u>register count</u> (in range [1..125]); must not exceed the boundary (first register number + register count <= 65537);</li>

             <li><b>6</b> - <u>register value</u> (in range [0..65535]);</li>

             <li><b>3</b> - <u>holding register count</u> (in range [0..125]); must not exceed the boundary (first register number + holding register count <= 65537);</li>

            <li><b>4</b> - <u>input register count</u> (in range [0..125]); must not exceed the boundary (first register number + input register count <= 65537);</li>

            <li><b>5</b> - <u>coil value</u> (in range [0..1]);</li>

             <li><b>6</b> - <u>holding register value</u> (in range [0..65535]);</li>

            <li><b>15</b> - <u>coil count</u> (in range [1..1968]); must not exceed the boundary (first coil number + coil count <= 65537); and <u>coil values</u> separated with commas, without spaces (e.g., <i>1,2,3,654,21,789</i>); there must be exactly as many values as specified (with coil count); each value must be in the range of [0..1].</li>

             <li><b>16</b> - <u>register count</u> (in range [1..123]); must not exceed the boundary (first register number + register count <= 65537); and <u>register values</u> separated with commas, without spaces (e.g., <i>1,2,3,654,21,789</i>); there must be exactly as many values as specified (with register count); each value must be in the range of [0..65535].</li>

             <li><b>16</b> - <u>register count</u> (in range [1..123]); must not exceed the boundary (first register number + register count <= 65537); and <u>register values</u> separated with commas, without spaces (e.g., <i>1,2,3,654,21,789</i>); there must be exactly as many values as specified (with register count); each value must be in the range of [0..65535].</li>

         </ul></li>

         </ul>

    </li>

    <!-- <li><b>Timeout count</b> - number of timeouts. (in range []) </li> -->

</ul>

</ul>