PCE Instruments PCE-HT 420IoT Users guide

Hygrometer

PCE-HT 420

INSTRUCTION MANUAL

PCE Americas Inc.
711 Commerce Way
Suite 8
Jupiter
FL-33458
USA
From outside US: +1
Tel: [phone]
Fax: [phone]
[e-mail]

www.pce-instruments.com/english

www.pce-instruments.com

PCE Instruments UK Ltd.

Southpoint Business Park

Hampshire / Southampton

United Kingdom, SO31 4RF

[e-mail]

Unit 11

Ensign way

From outside UK: +44

Tel: [phone]

Fax: [phone]

PCE-HT 420 (User's manual)

2 m

Table of Contents

1. Application ....................................................................................................................................... 3

2. The set of the monitor ....................................................................................................................... 4

3. Basic requirements, operational safety ............................................................................................. 4

4. Assembly .......................................................................................................................................... 5

4.1. Installation ..................................................................................................................................... 5

4.2. External connections diagram ....................................................................................................... 5

5. Operation .......................................................................................................................................... 6

5.1. Messages after powering the monitor up ....................................................................................... 6

5.2. Functions of the button .................................................................................................................. 7

5.3. Connection of the device – configuration ..................................................................................... 8

5.4. Functions of the monitor .............................................................................................................. 11

5.5. Description of PCE-HT 420 monitor reading field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

5.6. Ethernet 10/100-BASE-T ............................................................................................................ 13

5.6.1. Connection of 10/100 BASE-T interface ................................................................................. 14

5.6.2. Ethernet interface default parameters ....................................................................................... 16

5.6.2.1. Changing the parameters of Ethernet interface ..................................................................... 16

5.6.3 Web Server ................................................................................................................................ 17

5.6.3.1 General view ........................................................................................................................... 19

5.6.3.2. Selection of Web server user ................................................................................................. 21

5.6.3.3. Messages to the user .............................................................................................................. 21

5.6.3.4. Access to the archive file through the web server ................................................................. 23

5.6.3.5 Logic alarms .......................................................................................................................... 23

5.6.4 FTP Server ................................................................................................................................ 25

5.6.4.1 Selection of FTP user ............................................................................................................. 26

5.6.5 E-mail service ........................................................................................................................... 27

5.6.6 Modbus TCP/IP ......................................................................................................................... 30

5.6.6.1. Description of implemented functions ................................................................................. 31

5.6.6.2. Map of registers ..................................................................................................................... 31

5.6.6.3. Read-only registers. ............................................................................................................. 33

5.7. Firmware upgrade ........................................................................................................................ 34

5.8. Archiving measured values ....................................................................................................... . 35

5.8.1. The monitor memory structure .................................................................................... . . . . . . . . . . . . . 35

5.8.2. Configuration of archiving .................................................................................... . . . . . . . . . . . . . . . . . . . 35

5.8.3. File system internal memory ................................................................................. . . . . . . . . . . . . . . . . . . . 36

5.8.4. Structure of archive files ................................................................................. . . . . . . . . . . . . . . . . . . . . . . . . . 37

Additional accessories ................................................................................................. . . . . . . . . . . . . . . . . . . . .38

6.

Technical data ................................................................................................................... . . . . . . . . . . . . . . .40

7.

Ordering code ................................................................................................................. . . . . . . . . . . . . . . . . .. 42

8.

PCE-HT 420 (User's manual)

1. Application

3 m

PCE-HT 420 monitor is designed for continuous
measurement and conversion of relative humidity and ambient
temperature into digital form (Modbus TCP/IP , HTTP protocols).
The monitor programming is possible with the built-in web server.
The monitor has an LCD display with 2x16 characters. The device
allows you to send e-mail messages informing about the current
environmental parameters as well as events that lead to exceeding
the alarm values. The monitor is powered via Ethernet - PoE
(Power Over Ethernet) or standard DC jack.
Features of PCE-HT 420 monitor:

●measurement, display and archiving of ambient temperature,
relative humidity, dew point and absolute humidity,

●signaling when set alarm values are exceeded

●programming logic alarm outputs with reaction to the selected

input value.

●real-time clock function with clock supply support in case of the
monitor power failure

●registration of input signals in programmed time

●Ethernet 10/100 BASE-T
◦protocol: Modbus TCP/IP, HTTP, FTP,
◦services: web server, ftp server, DHCP client, SMTP client,

Values measured and calculated by the monitor:

⇒Temperature,
⇒relative humidity,
⇒dew point,
⇒absolute humidity,

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⇒wet bulb temperature,
⇒saturated vapor pressure,
⇒enthalpy.

All quantities and configuration parameters are available through
the embedded Web server, if the parameter is not visible, set it in
the tab Settings-> registers on the website.

Fig.1. View of PCE-HT 420 monitor:

2. The set of the monitor

●PCE-HT 420 monitor

●User’s manual

3. Basic requirements, operational safety

1 pc.
1 pc.

In terms of operational safety the monitor meets the

requirements of EN 61010-1.

Safety instructions

●The assembly and the installation of the electrical connections
may be carried out only by a duly qualified electrician.

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●Before turning on the monitor verify the connections.

●The monitor is intended for installation and use in industrial

electromagnetic environments.

●A switch or a circuit-breaker should be installed in the building or
facility. It should be located near the device, easily accessible to the
operator, and suitably marked.

4. Assembly

4.1. Installation

PCE-HT 420 monitor is mounted on a wall using a screw
connection. The monitor housing consists of an upper and a lower
part.

Fig.2 Location of mounting holes

4.2. External connections diagram

The monitor has 2 external slots:

- Ethernet por

- DC power socket

t 10/100 base-T

5.5 / 2.1 mm

and 1 button to reset the device to standard parameters - "Reset"

PCE-HT 420 (User's manual)

Fig.3 View of the upper part of PCE-HT 420 monitor

5. Operation

6 m

After wiring, mounting and powering the monitor is ready to
work with factory settings. The monitor can be programmed with the
built-in web server.

The following parameters can be programmed in the monitor:

•Ethernet interface settings,

•Modbus settings,

•Archive settings,

•Alarm settings,

•SMTP client settings - e-mail (only as unencrypted connection)

•System settings.

Caution: Do not remove the cover of the sensor as this may
damage the device!

5.1. Messages after powering the monitor up

After powe

r is turned on the display shows the name of the d

evice
and the manufacturer and software version. After about 4s the serial
number of the device is displayed and after another 4s the IP

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address in the network, if the device has been connected to
Ethernet network - the address can be static or obtained from
DHCP server.

Fig. 4 Startup messages of PCE-HT 420 monitor

5.2. Functions of the button

The device contains only one physical button for
restoring the factory settings or displaying the current IP address of
the monitor. This button is located on the connector panel – fig. 3.

- restoring factory parameters - after pressing and holding the
button for 10 seconds; Note: each successive restoration of factory
parameters enables or disables the service of obtaining network
address from a DHCP server, i.e. if the DHCP service is enabled
and restoring the factory parameters will be forced , the DHCP
service will be disabled (you will be informed about the change with
a message on the display) and the default static IP address will be
assigned to the device: 192.168.1.19 (subnet mask:

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255.255.255.0), another request for restoring the factory
parameters will enable the DHCP server service - the network
parameters will be obtained dynamically from the server;

- displaying the current IP address of the monitor – after a short
press of the button – about 1 sec.

5.3. Connection of the device – configuration

5.3.1. Connection of the monitor to the network equipped with
a DHCP server

The easiest way to connect an PCE-HT 420
monitor to Ethernet is to use the existing DHCP server,
which assigns communication parameters, i.e. IP address, subnet
mask, gateway, DNS address to the devices
being connected. In order to use the automatic configuration
with a DHCP server, make sure the monitor is running with DHCP
client service enabled - to do so, switch on the power of the monitor
and observe the initial messages:

a) message about the monitor operation

with DHCP client enabled – the displayed
IP address is the current address of the monitor acquired from
DHCP server;

b) message about the monitor operation
with a DHCP client disabled – the

displayed IP address is the current
address of the monitor set manually or the default address (after
restoration of default parameters); in order to obtain an address

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from a DHCP server you must restore the monitor to factory
defaults, p. 5.2, and restart the device - then you should see the
message a) with the IP address acquired from DHCP server.

In order to further configure the device a computer (tablet,
phone) must be connected to the same Ethernet network (also
with DHCP client enabled - automatic acquisition of IP address),
open a web browser and in the browser address field type the IP
address displayed by PCE-HT 420. This will display the login
screen to log the web server that will allow further configuration ­sign up to the administrator account, p. 5.6.3.2.

After gaining access to the full configuration we recommend
that you disable the DHCP client, leaving the acquired network
parameters unchanged – IP address, subnet mask, gateway, DNS
address will be stored as static parameters.

5.3.2. Connecting the monitor to the network without using
a DHCP server

In order to use the automatic configuration with a DHCP server,
make sure the monitor is running with DHCP client service disabled

- to do so, switch on the power of the monitor and observe the initial
messages:

a) message about the monitor operation

with DHCP client service enabled – the
displayed IP address is the current address of the monitor acquired
from DHCP server; to set the a static IP address factory parameters

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should be restored, p. 5.2, and the device should be restarted –
then a message should be displayed b) with the static default IP
address.

b) a message about the monitor operation

with disabled DHCP client service - the

displayed IP address is the current
address of the monitor set manually or the default IP address (after
restoring the default parameters), if the displayed address is
different from 192.168.1.19 the factory defaults should be restored
twice, p. 5.2;

In order to further configure the device a computer (tablet,
phone) must be connected to the same Ethernet network
(or directly to the monitor) and the automatic acquisition of network
parameters must be disabled. Then, the static parameters
corresponding to the default network parameters of PCE-HT 420
must be manually entered into the computer (tablet, phone) p.

5.6.2 (the same subnet mask and any IP address from the pool

192.168.1.X except for the address 192.168.1.19 assigned by
default to PCE-HT 420). After the connection, open your web
browser and type the default IP address 192.168.1.19. in the
address field of the browser. This will display the login screen to
the web server of the monitor that allows further configuration –
sign up to the administrator account, p. 5.6.3.2.
After logging in to the monitor web server it is possible to change
the network parameters according to our needs - especially the IP
address must be changed to make sure that the monitor does not

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have the default IP address, otherwise the configuration of other
monitors working in the same Ethernet network will be difficult.

5.4. Functions of the monitor

Monitor PCE-HT 420 performs the following functions:

•measurement of the ambient temperature and relative humidity,

•calculation of selected physical quantities,

•memory of minimum and maximum values measured and

calculated:

◦temperature,
◦relative humidity,
◦absolute humidity,
◦dew point.

5.5. Description of PCE-HT 420 monitor reading field

PCE-HT 420 is equipped with a backlit LCD display consisting
of two lines of 16 characters each. The top line of the display is
used for the presentation of measured values - temperature
and relative humidity and to display status pictographs of the file
system internal memory. The bottom line of the display is used for
presentation of the state of the internal memory, alarm no. 1 status,
time and date. During normal operation the monitor displays
measured values alternately with their symbols.

PCE-HT 420 (User's manual)

Fig. 5 Description of the monitor reading field

Tables 1, 2 show the symbols displayed on the LCD, and their

12 m

meanings.

Symbol Display mode Meaning

constant file system internal memory installed and

ready for operation
flashing error of file system internal memory
flashing file system internal memory full

flashing file system internal memory installed and

ready for operation, active FTP connection

constant alarm activity indicator - alarms 1, 2 active

constant alarm activity indicator - alarm 1 active

constant alarm activity indicator - alarm 2 active

Table1

constant alarm activity indicator - alarms inactive

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Table2

Symbol

Percentage of

internal memory

usage

87.5…100%

75…87.5%

62.5…75%

50…62.5%

37.5…50%

25…37.5%

12.5…25%

0…12.5%

When measuring ranges are overrun it is indicated by displaying
special characters on the top line of the LCD:

● - lower overrun of the range of the displayed value

●- upper overrun of the range of the displayed value

5.6. Ethernet 10/100-BASE-T

PCE-HT 420 monitors are equipped with Ethernet interface
for the connection (using RJ45 slot) to a local or global network
(LAN or WAN) and the use of network services implemented in the
monitors: Web server, FTP server, Modbus Slave TCP/IP, SMTP
client. In order to use the network services Ethernet
parameters of the monitor must be configured. Standard
Ethernet parameters of the monitor are shown in Table 4. The
basic parameter is the IP address of the monitor - by default

192.168.1.19, which must be unique within the network to which
we connect the device. The IP address can be assigned to the
monitor automatically by DHCP server present on the network
provided that the option to acquire IP address from DHCP server is
enabled. DHCP service is disabled by default, then the monitor
initializes with the default IP address

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allowing the user to change the IP address through the website.
Note: The monitor allows for up to 10 connections simultaneously!!

The applications implemented in the monitor use from 1 to 2
connections:

●Modbus TCP/IP - 1 connection

●Web server - minimum 1 connection

●FTP server - 2 connections

●SMTP client - 1 connection

5.6.1. Connection of 10/100 BASE-T interface

To access the Ethernet services, it is required to connect the
monitor to the network via the RJ45 slot located at the top of the
monitor, operating in accordance with TCP/IP.

Fig.6 View and numbering of RJ45 slot pins

Description of the monitor RJ45 slot diodes function:

●

yellow LED - illuminates when PCE-HT 420 is properly
connected to the Ethernet network 100 Base-T, does not light up
when PCE-HT 420 is not connected to the network or is connected
to 10-Base-T network.

●

green LED - Tx/Rx flickers when the monitor sends and receives
data, illuminates constantly when data is transmitted

In order to connect PCE-HT 420 to the network the User should
use

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twisted pair cable.

●U/FTP – twisted pair cable with each pair foiled,

●F/FTP – twisted pair cable with each pair foiled, additionally cable

with foil shield,

●S/FTP (formerly SFTP) – twisted pair cable with each pair foiled,
additionally cable with wire mesh shield,

●SF/FTP (formerly S-STP) – twisted pair cable with each pair foiled,
additionally with foil and wire mesh shield,

Categories of twisted pair cable according to the European
standard EN 50173 minimum: Class D (category 5) - for high-speed
local area networks, includes applications using the frequency band
up to 100 MHz. The description of the connection is shown in Table

3. For Ethernet interface the User should use twisted pair cable of
STP type (shielded) category 5 with RJ-45 connector with
conductors in colors (in accordance with the colors described in
table 3) acc. to the following standard:

●EIA/TIA 568A for both connectors at the so-called simple
connection of PCE-HT 420 to the network hub or switch,

●EIA/TIA 568A for the first connector and EIA/TIA 568B for the
second connector at the so-called patch cord connection
(crossover) used, among others, when connecting PCE-HT
420 to a computer.

Conduct

or no.

1 TX+ white-green white-orange
2 TX- green orange

Signal Conductor color acc. to standard

EIA/TIA 568A EIA/TIA 568B

Table 3

PCE-HT 420 (User's manual)

3 RX+ white-orange white-green
4 EPWR+ blue blue
5 EPWR+ white-blue white-blue
6 RX- orange green
7 EPWR- white-brown white-brown
8 EPWR- brown brown

16 m

5.6.2. Ethernet interface default parameters

No. Name Default value

Ta

ble 4

1. DHCP Enabled or disabled
(cycled when default parameters

restoration is forced)

2. IP Address 192.168.1.19

3. Subnet mask 255.255.255.0

4. Gateway 192.168.1.1

5. DNS 8.8.8.8

5.6.2.1. Changing the parameters of Ethernet interface

nging the parameters of the Ethernet interface is possible

Cha
through the built-in web server.

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17 m

Fig.7 View of the window to change the parameters of the

Ethernet interface

5.6.3 Web Server

Monitor PCE-HT 420 provides its own Web server that allows
remote monitoring of measured values and remote
configuration and readout of the monitor status. With the web page
the user can:

●obtain device information (serial number, execution code,
firmware version, bootloader version, variant (standard or special),

●preview the current measured values,

●read the status of the device,

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●select the language for the Web page,

●perform configuration

Access to the Web server is achieved by entering the monitor IP
address in the web browser, e.g .: http://192.168.1.19 (where

192.168.1.19 is set at the monitor). The standard port for web
server is port "80". Server port may be changed by the user.

Note: For proper web page operation a browser with JavaScript
enabled and compatible with XHTML 1.0 is required (all popular
browsers, Internet Explorer, version 8 minimum).

PCE-HT 420 (User's manual)

5.6.3.1 General view

19 m

Fig.8 General view of the main website

The function of each tile of the website:

1)The

view of measurements and after clicking on the tile graphs

with trends are displayed.

2)Ethernet interface settings.

3)Archive settings and information about memory usage and the
process of data dump to the file system memory.

4)Alarm settings and information about their status.

5)Information about the device, giving an individual name to the
monitor.

6)Setting the time, LCD display and configuration of our displayed
values - the groups of any of the 12 values of the monitor registers

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to which we can assign our own name and display it as a separate
tile on the website. Defined records can be archived and they
control the alarms.

7)Email configuration.

8)Logging off, return to the login page.

9)Configurable device name

10) Changing the language

11) Time to log off when inactive

Fig.9 View of the window to configure the groups of our own

records

Fig.10 View of a tile displaying a group of our 12 values

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5.6.3.2. Selection of Web server user

The monitor has two user accounts for the Web server secured by
individual passwords:

●user: ”admin”, password: ”admin” - access to configuration and

the preview of parameters

●user: ”user”, password: ”pass” - access to the preview of

parameters only.

●user: "guest" - access to the preview of the measured values on
the home page only, log on to the guest account does not require
entering a user name or password, it is enough to select "Login as a
guest” and then click on "Login"

Fig.11 View of the login window to the website

Calling the monitor’s IP address in the browser, for example
http://192.168.1.19 will display the start display in the browser
where the user must enter name and password. Additionally, you
can log in to the "guest” account, when you select "Login as a
guest" on the login page. "guest” user account is limited to view the
measured values on the main page. Log off occurs after 5 minutes
of inactivity.

5.6.3.3. Messages to the user

The web server is equipped with a system of messages

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to the user. If the user tries to save the settings
into the monitor, a message is returned on the status of such
operation. For mobile applications there is a user notification
system built-in the web browser.

Fig.12 View of the message window informing that

parameters have been correctly recorded in the device

Fig.13 View of the message window informing about incorrect

ata of the web form

d

Fig. 14 View of the message window informing about lack of

permission to view the website content.

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5.6.3.4. Access to the archive file through the web
server

PCE-HT 420 allows for access to archive files through the file
manager

implemented on the web server that allows the user to retrieve and
delete individual files. To start the archive file manager, click on the
tile Archive, and then click the button Browse arch. Files.

Fig.15 View of the window of the file manager on the web server

In order to download the file, click the file icon, and to delete a file,
click the trash can symbol next to the file icon.

5.6.3.5 Logic alarms

PCE-HT 420 is equipped with 2 logic alarm outputs. Each
alarm can

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operate in one of six modes. Fig. 17 shows the operation of alarm
in the following modes: n-on, n-off, on, off. The other two modes: h­on and h-off mean respectively, always On and always Off. These
modes are designed for manual simulation of alarm states.

Fig. 16 View of alarms configuration window

PCE-HT 420 (User's manual)

a) n-on

stan

Alarm status

alarmu

1
0

wył czony

Disabled

AL_L

zał czony

Enabled

AL_H Wielko steruj ca

25 m

c) off

stan

Alarm status

alarmu

1

zał czony zał czony

Enabled

0

wył czony

Disabled

Enabled

Wielko steruj caAL_L AL_H

Controlling quantityControlling quantity

b) n-off

stan

Alarm status

alarmu

1

zał czony

Enabled

0

Disabled

wył czony

Wielko

Controlling quantity

steruj caAL_L AL_H Wielko steruj caAL_L AL_H

d) on

stan

Alarm

alarmu

status

1
0

wył czony wył czony

Disabled

Enabled

zał czony

Disabled

Controlling quantity

AL_L - Lower threshold of the alarm
AL_H - Upper threshold of the alarm

Fig. 17 Types of alarms: a) n-on; b) n-off; c) on; d) off.

Note: In the case of alarm types n-on, n- off, on, off entering AL_L > AL_H will
disable the alarm.

In the "alarm output" tab the user can decide what action will be
performed following the change of the alarm state:

- Buzzer – audible alarm

- E-mail address 1 – sending an e-mail to recipient No. 1

- E-mail address 2 – sending an e-mail to recipient No. 2
It is possible to simultaneously select several options at once.
Note: If the user selects the audible alarm for alarm number 1 (2),

the same option should not be selected for alarm 2 (1).

5.6.4 FTP Server

FTP file sharing protocol is implemented in PCE-HT 420
monitors. The monitor acts as a server, allowing clients to
access the internal memory of the meter file system. Access to
files is possible using a computer, tablet with installed FTP client
or another device acting

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as FTP client. To transfer files using FTP the following ports are
normally used: "1025" - data port and "21" - command port. If
necessary, the user can change the port used by the FTP. Please
note,
that the configuration of the server and FTP client ports must be the
same.
FTP client program should work in passive mode, then the
connection is established fully by the client (the customer chooses
the data port). For file transfer with the monitor it is possible to use
maximum one connection at the same time, that is why the
maximum number of connections must be limited to "1” in the client
program.

Fig.18 View of FTP ports configuration window

5.6.4.1 Selection of FTP user

The monitor has two user accounts for the FTP server se
individual passwords:

•user: ”admin”,

password: “admin” - access to saving and reading

cured by

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files

•user: ”user”, password: ”passftp” - access to reading archive files

only.
FTP user names cannot be changed, however, it is possible to

change the password for each user - it is recommended to change
passwords for security reasons. The password must contain a
minimum of 4 characters. Password change is only possible
through the web page in "Ethernet” parameters group. Passwords
can have a maximum of 8 characters. If the password is lost ­making it impossible to use the FTP, the factory defaults of the
Ethernet interface must be restored through the Web site, or all
settings can be restored to the factory defaults using the "Reset"
button. 4.2. All standard parameters of the monitor including the
Ethernet parameters and password for FTP server users will be
restored:

user ”admin”

password: ”admin” ;

user ”user” password ”passftp”.

FileZilla can be used as the FTP client. By typing the monitor IP
address in the address field we can view and download archive
files.

5.6.5 E-mail service

PCE-HT 420 monitors have been equipped with a function to
send email messages using SMTP. To send a message a user
must provide authentication data to SMTP proxy server. It is
recommended that the server is located in the same network as the
device.

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28 m

Caution:

SMTP proxy server must support AUTH PLAIN
authentication for unencrypted connection.

The service allows a user to send information about alarm events
and information in the form of regular short e-mail messages that
contain the following information:

•The time at which the event occurred,

•The quantity that caused the event,

•The measured values which occurred at the moment of alarm

status change,

•The name of the device from which the information was sent.

PCE-HT 420 monitor has a memory buffer allowing for
storage of maximum 20 e-mail messages. If an e-mail cannot be
sent on a regular basis, for example, due to lack of connection
they are queued up one after the other until their number exceeds

20.
When the limit is exceeded, the subsequent messages will be lost.

In the case of transmission errors, wrong configuration or other
factors beyond the control of the device (e.g. Anti-spam protection
of SMTP server) messages may not reach their destination.

1)SMTP server address, for example, "smtp.wp.pl"

2)Address of the sender, .eg. "[e-mail]"

3)Username registered on the SMTP server

4)The password for the specified account on the SMTP server

5)The name of the first recipient to which the message is to be
delivered

6)The name of the second recipient

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7)The period of sending regular messages

Fig. 19 View of e-mail configuration window

The correct SMTP server port must be configured at "Ethernet" tile
in "SMTP” tab. For unencrypted connections usually ports 25 or 587
are used.

Fig. 20 View of SMTP port configuration window on "Ethernet” tile

To verify the configuration of e-mail, click on the "Send a test
message" button on "E-mail" tile and then, in order to determine the
configuration errors, watch the messages appearing in the upper
left corner of the website.

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30 m

5.6.6 Modbus TCP/IP

PCE-HT 420 monitors allow access to internal registers via
Ethernet and Modbus TCP/IP Slave. Modbus protocol functions
and structure of the records are described in points 5.5.6.1 –

5.5.6.3. In order to set up a connection it is necessary to set a
unique IP address for the monitor and to set the connection
parameters listed in Table 5.

Table 5

No. Description Default value

1.

2.

3.

4.

Device address for MODBUS TCP/IP
Port number of Modbus TCP
Time to close the port of Modbus TCP/IP service [s]
The maximum number of simultaneous connections

to Modbus TCP / IP service

1

502

60

2

The device’s address is the address of the device for Modbus TCP /

By setting the address of the monitor to "255" the monitor will

IP.
skip the analysis of the address in Modbus frame (broadcast mode).

PCE-HT 420 (User's manual)

31 m

Fig.21 View of Modbus TCP configuration parameters on "Ethernet”

tile

The implemented protocol is in accordance with the standard PI­MBUS-300 Rev G of Modicon Company.

5.6.6.1. Description of implemented functions

PCE-HT 420 monitors have the following MODBUS functions:

●03 (03h) – readout of group of register.

●04 (04h) – readout of group of input registers.

●17 (11 h) - identification of slave device.

5.6.6.2. Map of registers

In PCE-HT 420 monitor the data is placed in 16- and 32-bit
registers. Process variables and parameters of the monitor are
located in the address space of registers in a manner dependent
on the type of the variable. Bits in 16-bit registers are
numbered from the

PCE-HT 420 (User's manual)

32 m

youngest to the oldest (b0 ... b15). 32-Bit registers (4 Bytes) contain
floating point numbers in IEEE-754 standard. Order of bytes: B3 B2
B1 B0 – the oldest byte is sent first. 16-Bit registers representing
32-bit values in two subsequent registers are doubled in another
address area with the following bytes order: B1 B0 B3 B2 (Tab. 6).

The map of PCE-HT 420 registers is presented below.
Note: All given addresses are physical addresses.
In some computer programs, logical addressing is applied, then
addresses must be increased by 1.

Table 6

Address
range

6000-6198 float (32 bits) Value is placed in two successive 16-bit

7000 -7198 float (32 bits) Value is placed in two successive 16-bit

7500-7599 float (32 bits) Value is placed in 32-bit register. Registers are

Value type Description

registers. Registers contain the same data as
32-bit registers of 7500 range. Registers are
read-only. Bytes order (B1,B0,B3,B2)

registers. Registers contain the same data as
32-bit registers of 7500 range. Registers are
read-only. Bytes order (B3,B2,B1,B0)

read-only.

PCE-HT 420 (User's manual)

33 m

5.6.6.3. Read-only registers.

Value is

placed in

two

successive

16-bit

registers.

These

registers

contain the

same data

as 32-bit

registers of

7500 range.

7000/6000 7500 T o

Value is

placed in

32-bit

registers.

Name

Unit

Record(z)/readout(o)

o

C Measured temperature

Table 7

Unit name

7002/6002 7501 R
7004/6004 7502 DP o

H o % Measured relative humidity

o

C Calculated dew point
7006/6006 7503 AH o g/m3Calculated absolute humidity
7008/6008 7504 o

o

C Wet bulb temperature
7010/6010 7505 o hPA Saturated vapor pressure
7012/6012 7506 Enthalpy
7014/6014 7507 Reserved
7016/6016 7508 Reserved
7018/6018 7509 Reserved
7020/6020 7510 min T o
7022/6022 7511

max T o

o

C Minimum temperature

o

C Maximum temperature
7024/6024 7512 min RH o % Minimum relative humidity
7026/6026 7513 max RH o % Maximum relative humidity
7028/7028 7514 min DP o
7030/6030 7515 max DP o

o

C Minimum dew point

o

C Maximum dew point
7032/6032 7516 min AH o g/m3Minimum absolute humidity
7034/6034 7517 max AH o g/m3Maximum absolute humidity
7036/6036 7518 o Device ID
7038/6038 7519 Status
7040/6040 7520 % of internal archive usage
7042/6042 7521 Reserved
7044/6044 7522 Progress of internal archive

rewriting To the file system

7046/6046 7523 Current o - Current time

PCE-HT 420 (User's manual)

time

34 m

7048/6048 7524 Date - year o
7050/6050 7525 Month, day o

YYYY

MMDD

Current date - year

Current date - month, day
7052/6052 7526 Reserved
7054/6054 7527 o the amount of file system memory

available space (kB), value ”-1”

means a memory error
7056/6056 7528 o Total storage capacity of file system

memory (kB), value ”-1” means no

properly installed memory

7058/6058

...7072/6072

7074/6074 7537 o The fir

7529-

7536

o Reserved

st defined register displayed

7076/6076 7538 o The second defined register

displayed
7078/6078 7539 o The third defined register displayed

... …. ……….

7096/6096 7548 o The twelfth defined register

displayed

5.7. Firmware upgrade

Software updates are available from PCE Instruments.

PCE-HT 420 (User's manual)

35

m

5.8. Archiving measured values

5.8.1. The monitor memory structure

PCE-HT 420 monitors are normally equipped with 4MB of internal
memory for storing current data recorded by the monitor. The
monitor can record any parameter of the 4 measured values ­temperature, relative humidity, dew point and absolute
humidity. Additionally, a user can archive each of 12 defined

displayed quantities. Internal memory of the monitor allows for

storage of 534336 records. If the default 50% of the internal

memory is used (or other value defined by the user) the archive is

automatically rewritten to the file system memory. The memory is a

circular buffer. After the memory is full, the oldest data is

overwritten. The internal archive can be read, copied and deleted.

PCE-HT 420 monitors have file system internal memory of the size

of 8GB (memory size of the file system can be increased on request

or according to the needs of the manufacturer) to which the data

from the internal memory are automatically rewritten in the form of

files. Data can be downloaded via Ethernet using FTP or Web site.

Minimum archiving period is 10 seconds.

5.8.2. Configuration of archiving

Website is used to configure the archiving parameters. Archiving
can be continuous and conditional. Triggering conditional archiving
may be performed according to one of the four possibilities shown
in Fig. 23 (n-on, n-off, off, on). Continuous archiving is activated by
selecting h-on archiving type, and it is turned off by selecting the h­off option.

PCE-HT 420 (User's manual)

36

m

a) n-on

Archiwizacja

Archiving

1
0

wył czona

Disabled

b) n-off

Archiving

Archiwizacja

1

zał czona

Enabled

0

Ar_L

c) off

Archiwizacja

Archiving

zał czona

Enabled

Ar_H Wielko steruj ca

Controlling quantity

1

zał czona zał czona

Enabled

0

wył czona

Disabled

Enabled

d) on

Archiwizacja

Disabled

wył czona

Wielko

Controlling quantity

steruj caAr_L Ar_H Wielko steruj caAr_L Ar_H

Archiving

1
0

wył czona wył czona

Disabled

Enabled

zał czona

Disabled

Fig. 23 Types of conditional archiving

Wielko steruj caAr_L Ar_H

Controlling quantity

Controlling quantity

Ar_L - Lower threshold of archiving
Ar_H - Upper threshold of archiving

5.8.3. File system internal memory

PCE-HT 420 monitors are equipped with file system internal
memory. FAT and FAT32 file systems are supported. During
operation the monitor creates file directories containing historical
data.

During registration the monitor creates directories and files of the
file system in the internal memory. An example of the directory
structure is shown in Fig. 24.

Fig. 24 Directories structure in the memory.

PCE-HT 420 (User's manual)

37

m

Apart from the ARCH directory, in which the archived data is placed,
SYSTEM directory is also created on the card where the following
files are located:

- start.txt - date and time of the file system internal memory
installation (when the monitor is restarted after power failure)

- manual.pdf - current user’s manual

- enarch.gif – graphic file with info about alarms / archiving
configuration

Note: If these files are deleted, some elements of the website ­hints, instructions, may not be displayed; these files can be
removed after logging in FTP server to admin account.

Data in the memory is stored in files located in the directories with
names corresponding to the device name and the serial number ­see Fig. 24. Whereas the names of the files correspond to the date
of recording and they have the following format XXXX_YY.Dzz,
where XXXX

year , YY month. The format of the archive file
extension is Dzz, where "zz" is the subsequent number of the
archive file from a given month. For example, the first file in the
archive in the month of May 2016 will be 2016_05.D00, the next file:
2016_05.D01 etc. For a given month it is possible to create
maximum 32 files (*.D00 … *.D31). The file is changed
automatically when the file size reaches 29 MB.

5.8.4. Structure of archive files

Files containing archived data in the internal memory of

the file
system are structured as columns, where successive columns of
data are separated from each other by a tab character.
The first line of the file contains the columns header. Data records

are s

equentially arranged in rows and the fields of the record are

PCE-HT 420 (User's manual)

38

m

separated from each other by a tab character. View a sample
archive file with archiving of further 12 user’s displayed values is
shown in Fig. 25.

Fig. 25 Sample data file

Subsequent fields included in a row describing the record
have the following meanings:

●date – the date of the data registration, the date

separator character is "-"

●time – hour, minute, second of the recorded data, time
separator character is ” : ”

●T, RH, DP, AH, name1, user reg , …. – name of the value

to be archived, the default separator character is ” . ”
however, the separator can be changed to ” , ” by selecting
the proper option in the Archive window of the website.

6. Additional accessories

PCE-HT 420 monitors are available with additional
accessories such as D.C. and PoE IEEE 802.3af. power
supply units Table 7 shows the available items with their codes.

PCE-HT 420 (User's manual)

No. Accessory Appearance Ordering code Technical data

39

m

Table 8

1. 6 VDC
power
supply unit

2. PoE
power
supply

20-072-00-00094 Voltage: 6 V d.c. ± 5%

Maximum power: 6W*
Input voltage:

90...253 V a.c.
Operating temperature:

0...40oC*
Dimensio

63.6 x 29.5 x 45.6 mm*
Conductor length:

1.4 m ± 10%*
Plug: 5.5 / 2.1 mm
*power supply parameters can
change

20-090-00-00022 Input voltage:

100 – 240 VAC
Input frequency:
47 – 63 Hz
Current consumption: 0.35 A
max.
for 240 VAC
Output voltage: 48 VDC
Power output: 15.4 W
Operating temperature: 0 –
40oC
Dimensio
Weight: 0.2 kg

ns:

ns: 140 x 65 x 36 mm

3. power
cord for
PoE
power
supply

20-069-00-00146 conductor length: 1.8 m

PCE-HT 420 (User's manual)

7. Technical data

40

m

Basic parameters:

–measuring range of relative humidity (RH)

0...95 % without condensation
–intrinsic error of humidity processing

±3% of the range for RH = 10...90%
±5% in the remaining range

–hysteresis humidity measurement ± 1% RH
–basic range of temperature measurement (T) – 20...60 °C
–intrinsic error of temperature processing

±0.6o C in the range of 10...40o C
±1.0o C

–calculated quantities absolute humidity (a) [g/m

in the remaining range

dew point temperature (Td) [°C]

Ethernet Interface: 10/100-Base-T

- max. number of simultaneous connections 10

Nominal operating conditions:

3

]

– power s

upply 6 V d.c.

or PoE IEEE 802.3af

– power c
–ambient temperature – 20...23

onsumption < 2 VA

–air relative humidity: < 95%

…60 °C

PCE-HT 420 (User's manual)

41

–time of initial warm-up 15 minutes
–degree of protection provided by housing IP 20
– mounting on a wall
– weight <0.3 kg
–dimensions (120 x 80 x 25) mm
–operating position: with sensor directed to

the bottom

Electromagnetic compatibility

–Immunity to electromagnetic interference:
acc. to PN-EN 61000-6-2

m

–emission of electromagnetic interference:
acc. to PN-EN 61000-6-4

Safety requirements according to PN-EN 61010-1 standard

–installation category III
–degree of pollution 2
–operating voltage relative to earth 50V
–altitude < 2000m

Parameters of DC power supply unit (option):

–voltage 6 V d.c. ± 5%
–maximum power 6W

*

–input voltage 90...253 V a.c.

erating temperature 0...40 o C

–op
–dimensions 63.6 x 29.5 x 45.6 mm
–cord length 1.4 m ± 10%

–plug

5.5 / 2.1 mm

*

*

*

* power supply parameters can change

PCE-HT 420 (User's manual)

8. Ordering code

42

m

Table 9

Humidity and temperature monitor PCE­HT 420 type

Power supply*

6 V d.c. 1
6 V d.c. , PoE IEEE 802.3af 2

Accessories

none 0
6 V d.c. power supply unit 1

Version

Standard 00
Special** XX

Language

Polish P
English E
other** X

Acceptance tests:

without additional requirements 0
with quality inspection certificate 1
acc. to customer’s requirements X

X X XX X X

* - Monitor of PCE-HT 420 1XXXXX version require external supply voltage of 6 V
d.c. Monitors of PCE-HT 420 2XXXXX version can be supplied both from Ethernet
interface through PoE (Power over Ethernet), and from external power supply 6 V
d.c.

** - only after agreement with the manufacturer

Coding example:

PCE-HT 420-2100P1 means a monitor supplied by PoE IEEE

802.3af and

6 V d.c. with 6 V d.c.

power supply unit included in
standard version with Polish language version and quality
inspection certificate.