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# $Id: 98_ModbusAttr.pm
#
# generisches fhem Modul für Geräte mit Modbus-Interface
# verwendet Modbus.pm als Basismodul für die eigentliche Implementation des Protokolls.
#
# This file is part of fhem.
#
# Fhem is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# Fhem is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with fhem. If not, see .
#
##############################################################################
# Changelog:
#
# 2015-03-09 initial release
# 2015-07-22 added documentation for new features introduced in the base module 98_Modbus.pm
# that can be used here.
#
package main;
use strict;
use warnings;
#####################################
sub
ModbusAttr_Initialize($)
{
my ($modHash) = @_;
require "$attr{global}{modpath}/FHEM/98_Modbus.pm";
require "$attr{global}{modpath}/FHEM/DevIo.pm";
ModbusLD_Initialize($modHash); # Generic function of the Modbus module does the rest
$modHash->{AttrList} = $modHash->{AttrList} . " " . # Standard Attributes like IODEv etc
$modHash->{ObjAttrList} . " " . # Attributes to add or overwrite parseInfo definitions
$modHash->{DevAttrList}; # Attributes to add or overwrite devInfo definitions
}
1;
=pod
=begin html
ModbusAttr
ModbusAttr uses the low level Modbus module 98_Modbus.pm to provide a generic Modbus module for devices that can be defined by attributes similar to the way HTTPMOD works for devices with a web interface.
Prerequisites
-
This module requires the basic Modbus module which itsef DevIO which again requires Device::SerialPort or Win32::SerialPort module.
Define
define <name> ModbusAttr <Id> <Interval>
or
define <name> ModbusAttr <Id> <Interval> <Address:Port> <RTU|TCP>
The module connects to the Modbus device with Modbus Id <Id> through an already defined modbus device
or directly through Modbus TCP or Modbus RTU over TCP and actively requests data from that device every <Interval> seconds
Examples:
define WP ModbusAttr 1 60
to go through a serial interface managed by an already defined basic modbus device.
or
define WP ModbusAttr 5 60 192.168.1.122:504 TCP
to talk Modbus TCP
or
define WP ModbusAttr 3 60 192.168.1.122:8000 RTU
to talk Modbus RTU over TCP
Configuration of the module
The data objects (holding registers, input registers, coils or discrete inputs) of the device to be queried are defined using attributes. The attributes assign objects with their address to readings inside fhem and control
how these readings are calculated from the raw values and how they are formatted.
Objects can also be written to the device and attributes define how this is done.
Example:
define PWP ModbusAttr 5 30
attr PWP obj-h256-reading Temp_Wasser_ein
attr PWP obj-h256-expr $val/10
attr PWP obj-h258-reading Temp_Wasser_Aus
attr PWP obj-h258-expr $val/10
attr PWP obj-h262-reading Temp_Luft
attr PWP obj-h262-expr $val / 10
attr PWP obj-h770-reading Temp_Soll
attr PWP obj-h770-expr $val / 10
attr PWP obj-h770-set 1
attr PWP obj-h770-setexpr $val * 10
attr PWP obj-h770-max 32
attr PWP obj-h770-min 10
attr PWP obj-h770-hint 8,10,20,25,28,29,30,30.5,31,31.5,32
attr PWP dev-h-combine 5
attr PWP dev-h-defPoll 1
attr PWP room Pool-WP
attr PWP stateFormat {sprintf("%.1f Grad", ReadingsVal($name,"Temp_Wasser_Ein",0))}
attr PWP webCmd Temp_Soll
Attributes to define data objects start with obj- followed by a code that identifies the type and address
of the data object.
Modbus devices offer the following types of data objects: holding registers (16 bit objects that can be read and written), input registers (16 bit objects that can only be read), coils (single bit objects that can be read and written) or discrete inputs (single bit objects that can only be read).
The module uses the first character of these data object types to define attributes. Thus h770 refers to a holding register with the decimal address 770 and c120 refers to a coil with address 120. The address has to be specified as pure decimal number without any leading zeros or spaces.
attr PWP obj-h258-reading Temp_Wasser_Aus
defines a reading with the name Temp_Wasser_Aus that is read from the Modbus holding register at address 258.
With the attribute ending on -expr
you can define a perl expression to do some conversion or calculation on the raw value read from the device. In the above example the raw value has to be devided by 10 to get the real value.
An object attribute ending on -set
creates a fhem set option. In the above example the reading Temp_Soll can be changed to 12 degrees by the user with the fhem command set PWP Temp_Soll 12
The object attributes ending on -min
and -max
define min and max values for input validation and the attribute ending on -hint
will tell fhem to create a selection list so the user can graphically select the defined values.
To define general properties of the device you can specify attributes starting with dev-
. E.g. with dev-timing-timeout
you can specify the timeout when waiting for a response from the device. With dev-h-
you can specify several default values or general settings for all holding registers like the function code to be used when reading or writing holding registers. These attributes are optional and the module will use defaults that work in most cases.
dev-h-combine 5
for example allows the module to combine read requests to objects having an address that differs 5 or less into one read request. Without setting this attribute the module will start individual read requests for each object. Typically the documentation for the modbus interface of a given device states the maximum number of objects that can be read in one function code 3 request.
Set-Commands
are created based on the attributes defining the data objects.
Every object for which an attribute like obj-xy-set
is set to 1 will create a valid set option.
Get-Commands
All readings are also available as Get commands. Internally a Get command triggers the corresponding
request to the device and then interprets the data and returns the right field value. To avoid huge option lists in FHEMWEB, the objects visible as Get in FHEMWEB can be defined by setting an attribute obj-xy-showget
to 1.
Attributes
- do_not_notify
- readingFnAttributes
the following list of attributes can be applied to any data object by specifying the objects type and address in the variable part.
For many attributes you can also specify default values per object type (see dev- attributes later) or you can specify an object attribute without type and address (e.g. obj-len) which then applies as default for all objects:
- obj-[cdih][1-9][0-9]*-reading
define the name of a reading that corresponds to the modbus data object of type c,d,i or h and a decimal address (e.g. obj-h225-reading).
- obj-[cdih][1-9][0-9]*-name
defines an optional internal name of this data object (this has no meaning for fhem and serves mainly documentation purposes.
- obj-[cdih][1-9][0-9]*-set
if set to 1 then this data object can be changed (works only for holding registers and coils since discrete inputs and input registers can not be modified by definition.
- obj-[cdih][1-9][0-9]*-min
defines a lower limit to the value that can be written to this data object. This ist just used for input validation.
- obj-[cdih][1-9][0-9]*-max
defines an upper limit to the value that can be written to this data object. This ist just used for input validation.
- obj-[cdih][1-9][0-9]*-hint
this is used for set options and tells fhemweb what selection to display for the set option (list or slider etc.)
- obj-[cdih][1-9][0-9]*-expr
defines a perl expression that converts the raw value read from the device.
- obj-[cdih][1-9][0-9]*-map
defines a map to convert values read from the device to more convenient values when the raw value is read from the device or back when the value to write has to be converted from the user value to a raw value that can be written. Example: 0:mittig, 1:oberhalb, 2:unterhalb
- obj-[cdih][1-9][0-9]*-setexpr
defines a perl expression that converts the user specified value in a set to a raw value that can be sent to the device. This is typically the inversion of -expr above.
- obj-[cdih][1-9][0-9]*-format
defines a format string to format the value read e.g. %.1f
- obj-[cdih][1-9][0-9]*-len
defines the length of the data object in registers. It defaults to 1. Some devices store 32 bit floating point values in two registers. In this case you can set this attribute to two.
- obj-[cdih][1-9][0-9]*-unpack
defines the unpack code to convert the raw data string read from the device to a reading. For an unsigned integer in big endian format this would be "n", for a signed 16 bit integer in big endian format this would be "s>" and for a 32 bit big endian float value this would be "f>". (see the perl documentation of the pack function).
- obj-[cdih][1-9][0-9]*-revRegs
this is only applicable to objects that span several input registers or holding registers.
when they are read then the order of the registers will be reversed before
further interpretation / unpacking of the raw register string
- obj-[cdih][1-9][0-9]*-bswapRegs
this is applicable to objects that span several input or holding registers.
after the registers have been read, all 16-bit values are treated big-endian and are reversed to little-endian by swapping the two 8 bit bytes. This functionality is most likely used for reading (ASCII) strings from the device that are stored as big-endian 16-bit values.
example: original reading is "324d3130203a57577361657320722020". After applying bswapRegs, the value will be "4d3230313a2057576173736572202020"
which will result in the ASCII string "M201: WWasser ". Should be used with "(a*)" as -unpack value.
- obj-[cdih][1-9][0-9]*-decode
defines an encoding to be used in a call to the perl function decode to convert the raw data string read from the device to a reading. This can be used if the device delivers strings in an encoding like cp850 instead of utf8.
- obj-[cdih][1-9][0-9]*-encode
defines an encoding to be used in a call to the perl function encode to convert the raw data string read from the device to a reading. This can be used if the device delivers strings in an encoding like cp850 and after decoding it you want to reencode it to e.g. utf8.
- obj-[cdih][1-9][0-9]*-showget
every reading can also be requested by a get command. However these get commands are not automatically offered in fhemweb. By specifying this attribute, the get will be visible in fhemweb.
- obj-[cdih][1-9][0-9]*-poll
if set to 1 then this obeject is included in the cyclic update request as specified in the define command. If not set, then the object can manually be requested with a get command, but it is not automatically updated each interval. Note that this setting can also be specified as default for all objects with the dev- atributes described later.
- obj-[cdih][1-9][0-9]*-polldelay
this attribute allows to poll objects at a lower rate than the interval specified in the define command. you can either specify a time in seconds or number prefixed by "x" which means a multiple of the interval of the define command.
if you specify a normal numer then it is interpreted as minimal time between the last read and another automatic read. Please note that this does not create an individual interval timer. Instead the normal interval timer defined by the interval of the define command will check if this reading is due or not yet. So the effective interval will always be a multiple of the interval of the define.
- dev-([cdih]-)*read
specifies the function code to use for reading this type of object. The default is 3 for holding registers, 1 for coils, 2 for discrete inputs and 4 for input registers.
- dev-([cdih]-)*write
specifies the function code to use for writing this type of object. The default is 6 for holding registers and 5 for coils. Discrete inputs and input registers can not be written by definition.
- dev-([cdih]-)*combine
defines how many adjacent objects can be read in one request. If not specified, the default is 1
- dev-([cdih]-)*defLen
defines the default length for this object type. If not specified, the default is 1
- dev-([cdih]-)*defFormat
defines a default format string to use for this object type in a sprintf function on the values read from the device.
- dev-([cdih]-)*defExpr
defines a default Perl expression to use for this object type to convert raw values read.
- dev-([cdih]-)*defUnpack
defines the default unpack code for this object type.
- dev-([cdih]-)*defRevRegs
defines that the order of registers for objects that span several registers will be reversed before
further interpretation / unpacking of the raw register string
- dev-([cdih]-)*defBswapRegs
per device default for swapping the bytes in Registers (see obj-bswapRegs above)
- dev-([cdih]-)*defDecode
defines a default for decoding the strings read from a different character set e.g. cp850
- dev-([cdih]-)*defEncode
defines a default for encoding the strings read (or after decoding from a different character set) e.g. utf8
- dev-([cdih]-)*defPoll
if set to 1 then all objects of this type will be included in the cyclic update by default.
- dev-([cdih]-)*defShowGet
if set to 1 then all objects of this type will have a visible get by default.
- dev-timing-timeout
timeout for the device (defaults to 2 seconds)
- dev-timing-sendDelay
delay to enforce between sending two requests to the device. Default ist 0.1 seconds.
- dev-timing-commDelay
delay between the last read and a next request. Default ist 0.1 seconds.
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