Available Modbus Commands And Data Areas; Address Configuration; Connections; Modbus Table Content - Elsteam EHPN Series Operating And Maintenance Manual

12.3.1 Available Modbus commands and data areas

The commands implemented are as follows:
Command Description
03 (hex 0x03) Resource reading command
06 (hex 0x06) Resource writing command

12.4 Address configuration

TheRS-485communicationserialportcanbeusedtoconfigurethedevice,theparameters,thestatusesandtheModbus
variables and to monitor device operation using Modbus protocol.
The device address in a Modbus message is set by parameter LA1.
The address 0isonlyusedforbroadcastmessages,recognisedbyallslaves.Slavedevicesdonotrespondtoabroadcast
message.
Seriallineconfigurationparameters,whichcanbeaccessedviatheuserinterfacemenu,are:
Par. Description
LA1 Modbus communication protocol address.
Modbus transmission speed (baud rate).
Lb1
0=2400;1=4800;2=9600;3 =19200;4=38400.
Modbus parity bit.
LP1
0=None;1=Odd;2=Even.
Modbus stop bit.
LS1
0=1stopbit;1=2stopbits.
The RS-485 RTU serial line has the following characteristics:
• RTU mode;
• Bit: 8 bit

12.5 Connections

Fortheentiresystemtoworkproperly,includingtheRS-485RTUserialline,observetheinstructionsprovidedinchapter"6.
ELECTRICAL CONNECTIONS" ON PAGE 38.
Inparticular,takecaretomaketheconnectionscorrectly,observingtheinstructionsinsection
"6.5 ELECTRICAL CONNECTIONS" ON PAGE 46

12.6 Modbus table content

Table content description
The table below contains the information required to access the resources properly and directly.
There are two tables:
•  T heModbusaddresstable,whichcontainsalltheconfigurationparametersforthedeviceandthecorresponding
Modbus addresses;
• Modbusresourcetable,whichcontainsallthestatus(I/O)andalarmresourcesinthedevicememory.
Description of columns in the Table of addresses
• Par.:Listofconfigurabledeviceparameters;
• Description: Indicates parameter operation and any possible selections;
• MU: Measurement unit relating to the parameter;
• Range: Describes the interval of values that the parameter can assume. This can be correlated with other instrument
parameters (indicated with the parameter code).
NOTE: if the actual value is outside the permitted limits for that parameter (for example, because other parameters
defining the aforementioned limits have been altered), the value of the violated limit is displayed instead of the actual
value;
• Val. Adr.: Indicates the address of the Modbus register containing the resource you want to access;
• R/W: Indicates the option of reading or writing the resource:
• R: The resource is read-only;
• W: The resource is write-only;
• R/W: The resource can be both read and written.
• CPL:WhenthefieldsindicatesY,thevaluereadbytheregisterneedstobeconvertedbecausethevaluerepresentsa
number with a sign. In the other cases the value is always positive or zero.
• DATA SIZE: Indicates the size in data bits:
• DWORD =32bit
• DOUBLE =32bit
• WORD=16bit
• Byte=8bit
• The "n"bits=0...15bitdependingonthevalueof"n"
924EHPNE4.01 - EHPN series humidifiers | 93 | Modbus RTU functions and resources |
MU Range Default
--- 0...247 247
--- 0...4 4
--- 0...2 2
--- 0/1 0
02/2024