This adapter uses Sentry libraries to automatically report exceptions and code errors to the developers. For more details and for information how to disable the error reporting see Sentry-Plugin Documentation! Sentry reporting is used starting with js-controller 3.0.
Implementation of ModBus Slave and Master for ioBroker. The following types are supported:
- Modbus RTU over serial (master)
- Modbus RTU over TCP (master)
- Modbus TCP (slave, master)
IP address of modbus partner.
TCP Port of modbus partner if configured as master (client) or own port if configured as slave(server).
Modbus Device ID. Important if TCP/Modbus bridge is used.
Slave(Server) or Master(Client).
Normally, all registers can have address from 0 to 65535. By using of aliases, you can define virtual address fields for every type of registers. Normally:
- discrete inputs are from 10001 to 20000
- coils are from 1 to 1000
- input registers are from 30001 to 40000
- holding registers are from 40001 to 60000
Every alias will be mapped internally to address, e.g., 30011 will be mapped to input register 10. and so on.
Used for binary inputs and coils.
Without this flag the bits will be addressed from like: 0 => 15, 1 => 14, 2 => 13, ..., 15 => 0.
With this flag activated the bits will be addressed as: 0 => 0, 1 => 1, 2 => 2, ..., 15 => 15.
Normally, the coils and the discrete inputs addresses are aligned to 16 bits. Like addresses from 3 to 20 will be aligned to 0 up 32. If this option is active, the addresses will not be aligned.
If slave does not support "write multiple registers" command, you can activate it to get warnings, when the multiple registers will be written.
If slave only supports "write multiple registers" command, you can activate so the registers will be written always with FC15/FC16 command.
How many digits after comma for float and doubles.
Cyclic poll interval (Only relevant for master)
Reconnection interval (Only relevant for master)
Timeout for read requests in milliseconds. If no response is received from a slave in this time, the connection will be terminated.
If pulse used for coils, this defines the interval in milliseconds how long is the pulse.
Wait time between polling of two different device IDs in milliseconds.
Maximal length of command READ_MULTIPLE_REGISTERS as number of registers to read.
Some systems require first "write request" to deliver the data on "read request". You can force this mode by setting of the "Max read request length" to 1.
Notice: Some USB Modbus solutions (e.g. based on socat) can have trouble to work with serialport npm module.
There is a software Modbus RTU <-> Modbus RTU over TCP gateway to enable using of serial RTU over TCP protocol.
Both solutions RTU over TCP and TCP work well.
Delay between two read requests in ms. Default 0.
Delay between two write requests in ms. Default 0.
Normally, if the value has not changed, it will not be written into ioBroker. This flag allows updating the value's timestamp by every cycle.
Do not add address in the generated ioBroker iD. 10_Input10 vs Input10.
With this flag the Name will be Inputs.Input10. Without => Inputs_Input10.
Modbus address to read.
In case there are multiple slaves, then this is the ID if not the default one that is given in global config.
This is the name for the Parameter.
Parameter description.
Unit of the Parameter.
Datatype to read from Bus. For details about the possible data types see section Data types.
Length of parameter. For the most parameters, this is determined based on the data type, but for Strings this defines the length in Bytes / characters.
This factor is used to multiply the read value from Bus for static scaling. So the calculation looks like following val = x * Factor + Offset.
This offset is added to the read value after above multiplication. So the calculation looks like following val = x * Factor + Offset.
This field can be used for advanced calculations if Factor and Offset are not sufficient. If this field is set, then the Factor and Offset fields are ignored. The Formula is executed by the eval() function. Therefore, all common functions are supported. Especially the Math functions. The formula must comply with Javascript syntax, therefore, also take care about upper and lower cases.
In the formula, "x" has to be used for the read value from Modbus. E.g. x * Math.pow(10, sf['40065'])
Using the "sf" array (see above example), you can access other read modbus values if they are flagged as "Scale Factor" in the config (see below info on "SF" flag).
If the formula cannot be evaluated during runtime, then the Adapter writes a warning message to the log.
Another use case for formulas could also be to prevent implausible data with a formula like x > 2000000 ? null : x
ioBroker role to assign.
ioBroker room to assign.
If activated, the values are polled in a predefined interval from slave.
Write pulse
Cyclic write
Use value as a scaling factor.
This is needed to be used by dynamic scaling factors which are on some systems provided through values on interface.
If a value is marked with this flag, then the value will be stored into a variable with the following naming convention: sf['Modbus_address'].
This variable can be then later used in any formula for other parameters. E.g., the following formula can set: (x * sf['40065']) + 50;
-
uint16be-Unsigned 16 bit (Big Endian): AABB => AABB -
uint16le-Unsigned 16 bit (Little Endian): AABB => BBAA -
int16be-Signed 16 bit (Big Endian): AABB => AABB -
int16le-Signed 16 bit (Little Endian): AABB => BBAA -
uint32be-Unsigned 32 bit (Big Endian): AABBCCDD => AABBCCDD -
uint32le-Unsigned 32 bit (Little Endian): AABBCCDD => DDCCBBAA -
uint32sw-Unsigned 32 bit (Big Endian Word Swap): AABBCCDD => CCDDAABB -
uint32sb-Unsigned 32 bit (Big Endian Byte Swap): AABBCCDD => DDCCBBAA -
int32be-Signed 32 bit (Big Endian): AABBCCDD => AABBCCDD -
int32le-Signed 32 bit (Little Endian): ABBCCDD => DDCCBBAA -
int32sw-Signed 32 bit (Big Endian Word Swap): AABBCCDD => CCDDAABB -
int32sb-Signed 32 bit (Big Endian Byte Swap): AABBCCDD => DDCCBBAA -
uint64be-Unsigned 64 bit (Big Endian): AABBCCDDEEFFGGHH => AABBCCDDEEFFGGHH -
uint64le-Unsigned 64 bit (Little Endian): AABBCCDDEEFFGGHH => HHGGFFEEDDCCBBAA -
uint8be-Unsigned 8 bit (Big Endian): AABB => BB -
uint8le-Unsigned 8 bit (Little Endian): AABB => AA -
int8be-Signed 8 bit (Big Endian): AABB => BB -
int8le-Signed 8 bit (Little Endian): AABB => AA -
floatbe-Float (Big Endian): AABBCCDD => AABBCCDD -
floatle-Float (Little Endian): AABBCCDD => DDCCBBAA -
floatsw-Float (Big Endian Word Swap): AABBCCDD => CCDDAABB -
floatsb-Float (Big Endian Byte Swap): AABBCCDD => DDCCBBAA -
doublebe-Double (Big Endian): AABBCCDDEEFFGGHH => AABBCCDDEEFFGGHH -
doublele-Double (Little Endian): AABBCCDDEEFFGGHH => HHGGFFEEDDCCBBAA -
string-String 8 bit (Zero-end): ABCDEF\0 => ABCDEF\0 -
stringle-String 8 bit (Little Endian, Zero-end): ABCDEF\0 => BADCFE\0 -
string16-String 16 bit (Zero-end): \0A\0B\0C\0D\0E\0F\0\0 => ABCDEF\0 -
string16le-String 16 bit (Little Endian, Zero-end): A\0B\0C\0D\0E\0F\0\0\0 => ABCDEF\0 -
rawhex-String with value in hex representation AABBCCDD.... => AABBCCDD....
The following description was copied from here
The point-to-point Modbus protocol is a popular choice for RTU communications if for no other reason that its basic convenience. The protocol itself controls the interactions of each device on a Modbus network, how device establishes a known address, how each device recognizes its messages and how basic information is extracted from the data. In essence, the protocol is the foundation of the entire Modbus network.
Such a convenience does not come without any complications, however, and Modbus RTU Message protocol is no exception. The protocol itself was designed based on devices with a 16-bit register length. Consequently, special considerations were required when implementing 32-bit data elements. This implementation settled on using two consecutive 16-bit registers to represent 32 bits of data or essentially 4 bytes of data. It is within these four bytes of data that single-precision floating point data can be encoded into a Modbus RTU message.
Modbus itself does not define a floating point data type, but it is widely accepted that it implements 32-bit floating point data using the IEEE-754 standard. However, the IEEE standard has no clear definition of byte order of the data payload. Therefore, the most important consideration when dealing with 32-bit data is that data is addressed in the proper order.
For example, the number 123/456.00 as defined in the IEEE 754 standard for single-precision 32-bit floating point numbers appears as follows:
The effects of various byte orderings are significant. For example, ordering the 4 bytes of data that represent 123456.00 in a B A D C sequence in known as a “byte swap”. When interpreted as an IEEE 744 floating point data type, the result is quite different:
Ordering the same bytes in a “C D A B” sequence is known as a “word swap”. Again, the results differ drastically from the original value of 123456.00:
Furthermore, both a byte swap and a word swap would essentially reverse the sequence of the bytes altogether to produce yet another result:
Clearly, when using network protocols such as Modbus, strict attention must be paid to how bytes of memory are ordered when they are transmitted, also known as the ‘byte order’.
The Modbus protocol itself is declared as a ‘big-Endian’ protocol, as per the Modbus Application Protocol Specification, V1.1.b:
Modbus uses a “big-Endian” representation for addresses and data items. This means that when a numerical quantity larger than a single byte is transmitted, the most significant byte is sent first.
Big-Endian is the most commonly used format for network protocols – so common, in fact, that it is also referred to as ‘network order’.
Given that the Modbus RTU message protocol is big-Endian, in order to successfully exchange a 32-bit datatype via a Modbus RTU message, the endianness of both the master, and the slave must be considered. Many RTU master and slave devices allow specific selection of byte order, particularly in the case of software-simulated units. It only has to be ensured that both units are set to the same byte order.
As a rule of thumb, the family of a device’s microprocessor determines its endianness. Typically, the big-Endian style (the high-order byte is stored first, followed by the low-order byte) is generally found in CPUs designed with a Motorola processor. The little-Endian style (the low-order byte is stored first, followed by the high-order byte) is generally found in CPUs using the Intel architecture. It is a matter of personal perspective as to which style is considered ‘backwards’.
If, however, byte order and endianness are not a configurable option, you will have to determine how to interpret the byte. This can be done requesting a known floating-point value from the slave. If an impossible value is returned, i.e., a number with a double-digit exponent or such, the byte ordering will most likely need modification.
The FieldServer Modbus RTU drivers offer several function moves that handle 32-bit integers and 32-bit float values. More importantly, these function moves consider all different forms of byte sequencing. The following table shows the FieldServer function moves that copy two adjacent 16-bit registers to a 32-bit integer value.
| Function Keyword | Swap Mode | Source Bytes | Target Bytes |
|---|---|---|---|
| 2.i16-1.i32 | N/A | [ a b ] [ c d ] | [ a b c d ] |
| 2.i16-1.i32-s | byte and word swap | [ a b ] [ c d ] | [ d c b a ] |
| 2.i16-1.i32-sb | byte swap | [ a b ] [ c d ] | [ b a d c ] |
| 2.i16-1.i32-sw | word swap | [ a b ] [ c d ] | [ c d a b ] |
The following table shows the FieldServer function moves that copy two adjacent 16-bit registers to a 32-bit floating point value:
| Function Keyword | Swap Mode | Source Bytes | Target Bytes |
|---|---|---|---|
| 2.i16-1.ifloat | N/A | [ a b ] [ c d ] | [ a b c d ] |
| 2.i16-1.ifloat-s | byte and word swap | [ a b ] [ c d ] | [ d c b a ] |
| 2.i16-1.ifloat-sb | byte swap | [ a b ] [ c d ] | [ b a d c ] |
| 2.i16-1.ifloat-sw | word swap | [ a b ] [ c d ] | [ c d a b ] |
The following table shows the FieldServer function moves that copy a single 32-bit floating point value to two adjacent 16-bit registers:
| Function Keyword | Swap Mode | Source Bytes | Target Bytes |
|---|---|---|---|
| 1.float-2.i16 | N/A | [ a b ] [ c d ] | [ a b ][ c d ] |
| 1.float-2.i16-s | byte and word swap | [ a b ] [ c d ] | [ d c ][ b a ] |
| 1.float-2.i16-sb | byte swap | [ a b ] [ c d ] | [ b a ][ d c ] |
| 1.float-2.i16-sw | word swap | [ a b ] [ c d ] | [ c d ][ a b ] |
Given the various FieldServer function moves, the correct handling of 32-bit data is dependent on choosing the proper one. Observe the following behavior of these FieldServer function moves on the known single-precision decimal float value of 123456.00:
| 16-bit Values | Function Move | Result | Function Move | Result |
|---|---|---|---|---|
| 0x2000 0x47F1 | 2.i16-1.float | 123456.00 | 1.float-2.i16 | 0x2000 0x47F1 |
| 0xF147 0x0020 | 2.i16-1.float-s | 123456.00 | 1.float-2.i16-s | 0xF147 0X0020 |
| 0x0020 0xF147 | 2.i16-1.float-sb | 123456.00 | 1.float-2.i16-sb | 0x0020 0xF147 |
| 0x47F1 0x2000 | 2.i16-1.float-sw | 123456.00 | 1.float-2.i16-sw | 0x47F1 0x2000 |
Notice that different byte and word orderings require the use of the appropriate FieldServer function move. Once the proper function move is selected, the data can be converted in both directions.
Of the many hex-to-floating point converters and calculators that are available in the Internet, very few actually allow manipulation of the byte and word orders. One such utility is located at www.61131.com/download.htm where both Linux and Windows versions of the utilities can be downloaded. Once installed, the utility is run as an executable with a single dialog interface. The utility presents the decimal float value of 123456.00 as follows:
One can then swap bytes and/or words to analyze what potential endianness issues may exist between Modbus RTU master and slave devices.
With export / import functionality, you can convert all register data (only of one type) to TSV (Tab separated values) file and back to easily copy data from one device to another or to edit register in Excel.
You can share your schemas with other users in modbus-templates or you can find some register schemas there.
There are some programs in folder test to test the TCP communication:
- Ananas32/64 is a slave simulator (only holding registers and inputs, no coils and digital inputs)
- RMMS is master simulator
- mod_RSsim.exe is a slave simulator. It can be that you need Microsoft Visual C++ 2008 SP1 Redistributable Package to start it (because of SideBySide error).
- [ ] Parse files on https://github.com/ioBroker/modbus-templates and allow to import them directly from adapter
- (PLCHome) Warning regarding scale factor due to incorrect check: "Calculation of a scaleFactor which is based on another scaleFactor seems strange."
- (PLCHome) String based on 16 bit values big endian as well as little endian
- (PLCHome) Raw data as a hex string
- (PLCHome) Fix issue stringle was always converted to number for slave
- (PLCHome) Enable formula for strings and hex strings
- (nkleber78) Implement the connection keepAlive
- (bluefox) Better tooltips in settings
- (bluefox) GUI packages updated
- (bluefox) Added help for settings
- (bluefox) Minimal supported node.js version is 16
- (clausmuus) fixed reconnect of serial communication
- (bluefox) GUI packages updated
- (Apollon77) Prevent some crash cases reported by Sentry
- (bluefox) Corrected the coils reading in slave mode
- (bluefox) Corrected type of connection indicator
- (bluefox) Fixed error with mutli-devices
- BREAKING: All space characters will be replaced with underscores now in the Objects IDs, not only the first one.
- (Apollon77) Catch error reported by sentry when invalid Master port is entered
- (bluefox) GUI migrated to mui-v5
- (Apollon77/UncleSamSwiss) Prevent invalid state log
- (bluefox) Updated serial port package
- (bluefox) Minimal node.js version is 12
- (Apollon77) Catch errors in tasks processing to prevent crashes
- (Apollon77) Catch errors in tasks processing to prevent crashes
- (Apollon77) make sure generated IDs do not end with "."
- (nkleber78) Fixed issue with sorting
- (bluefox) Corrected the calculations with scaling factor
- (bluefox) Read times were optimized
- (bluefox) Corrected import of last line
- (Apollon77) Make sure that slave reconnections at least wait 1000ms to allow old connectio to close properly
- (bluefox) Corrected the error with write single registers
- (bluefox) Changed edit behaviour
- (Apollon77) Fix crash case on writing floats (Sentry IOBROKER-MODBUS-2D)
- (bluefox) Corrected addressing with aliases in GUI
- (bluefox) Corrected addressing with aliases
- (bluefox) Corrected the "write multiple registers" option
- (bluefox) GUI bugs were corrected
- (bluefox) Added output of error codes
- (nkleber78) Corrected issue with the scale factors
- (bluefox) New react GUI added
- (bluefox) Add new option: Use only Write multiple registers, read interval
- (bluefox) fixed the configuration dialog for "input registers" in slave mode
- (Apollon77) Allow usage of write-only (no poll) states
- (Apollon77/TmShaz) F Write multiple registers
- (prog42) create states of type string with default value of type string
- (Apollon77) Prevent a crash case (Sentry IOBROKER-MODBUS-20)
- (Apollon77) Better handle invalid responses
- (Sierra83) also support ttyXRUSB0 style devices
- (Apollon77) Catch value encoding error and do not crash adapter (Sentry IOBROKER-MODBUS-1W)
- (Apollon77) add a meta object as instance object
- (Apollon77) prevent a rash case (Sentry IOBROKER-MODBUS-1S)
- (Apollon77) prevent a crash case (Sentry IOBROKER-MODBUS-1R)
- (nkleber78) Fixed formula where return keyword was missing
- (nkleber78) Added the possibility to use formulas for values
- (Apollon77) fix admin serial port selection
- (nkleber78) Corrected: the exported data cannot be imported without modification
- (Apollon77) Prevent crash case (Sentry IOBROKER-MODBUS-1C)
- (Apollon77) Fix some Sentry crash reports (IOBROKER-MODBUS-N)
- (bluefox) Fix some Sentry crash reports (IOBROKER-MODBUS-J)
- (Apollon77) Fix some Sentry crash reports (IOBROKER-MODBUS-F)
- (Apollon77) Fix some Sentry crash reports (IOBROKER-MODBUS-4, IOBROKER-MODBUS-7, IOBROKER-MODBUS-6)
- (Apollon77) Change the way adapter restarts when reconnections do not help
- (Apollon77) fix scheduled restart
- (Apollon77) fix serialport list for Admin
- (Apollon77) Add Sentry crash reporting when used with js-controller >=3.x
- (Apollon77) Make sure that regular adapter stops do not terminate the process, so that scheduled restarts still work
- (Apollon77) update serialport, support nodejs 12/14
- (bluefox) Added device ID by export/import
- (bluefox) Added the "write interval" parameter
- (bluefox) Added the disabling of write multiple registers
- (bluefox) Corrected error after refactoring
- (compton-git) Decodes 0xFF00 as coil ON
- (BlackBird77) Fixes for Serial Timeouts done
- (bluefox) Refactoring
- (Apollon77) Support for nodejs 12 added, nodejs 4 is no longer supported!
- (Bjoern3003) Write registers was corrected
- (bluefox) The server mode was fixed
- (bluefox) rtu-tcp master mode was fixed
- (bluefox) Fixed the rounding of numbers
- (bluefox) The error with blocks reading was fixed
- (bluefox) The block reading for discrete values was implemented
- (bluefox) Added the support of multiple device IDs
- (Apollon77) Optimize reconnect handling
- (bluefox) Little endian strings added
- (Apollon77) Upgrade Serialport Library
- (bluefox) Fixed read of coils
- (Apollon77) Several Fixes
- (bluefox) Create all states each after other
- (Apollon77) Do not recreate all data points on start of adapter
- (ykuendig) Multiple optimization and wording fixes
- (bluefox) fix serial RTU
- (Apollon77) update serialport library for node 6.x compatibility
- (bluefox) Use old version of jsmodbus
- (bluefox) backward compatibility with 0.3.x
- (bluefox) better buffer handling on tcp and serial
- (bluefox) Fix write of holding registers
- (bluefox) Support of ModBus RTU over serial and over TCP (only slave)
- (Apollon77) Fix wrong byte count in loop
- (bluefox) fix lost of history settings.
- (bluefox) Use always write_multiple_registers by write of holding registers.
- (bluefox) add special read/write mode if "Max read request length" is 1.
- (bluefox) add cyclic write for holding registers (fix)
- (bluefox) add cyclic write for holding registers
- (bluefox) add doubles and fix uint64
- (bluefox) fix holding registers
- (bluefox) fix import from text file
- (bluefox) fix error with length of read block (master)
- (bluefox) support of read blocks and maximal length of read request (master)
- (bluefox) can define fields by import
- (bluefox) add round settings
- (bluefox) add deviceID
- (bluefox) slave supports floats, integers and strings
- (bluefox) add different types for inputRegisters and for holding registers ONLY FOR MASTER
- (bluefox) fix names of objects if aliases used
- (bluefox) fix error add new values
- (bluefox) fix error with master
- (bluefox) implement slave
- (bluefox) change addressing model
- (bluefox) initial commit
The MIT License (MIT)
Copyright (c) 2015-2024 Bluefox dogafox@gmail.com
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
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