PCE Americas PCE-HT 420 User manual

PCE Americas Inc.
711 Commerce Way
Suite 8
Jupiter
FL-33458
USA
From outside US: +1
Tel: [phone]
Fax: [phone]
[email protected]
www.pce-instruments.com/english
www.pce-instruments.com
PCE Instruments UK Ltd.
Unit 11
Southpoint Business Park
Ensign way
Hampshire / Southampton
United Kingdom, SO31 4RF
From outside UK: +44
Tel: [phone]
Fax: [phone]
[email protected]
HVAC Meter
PCE-HT 420
INSTRUCTION MANUAL

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
6.
Additional accessories.................................................................................................................... .38
7.
Technical data................................................................................................................................. .40
8.
Ordering code...................................................................................................................................42

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1. Application
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
1 pc.
●PCE-HT 420 monitor
●User’s manual
1 pc.
3. Basic requirements, operational safety
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 port 10/100 base-T
- DC power socket 5.5 / 2.1 mm
and 1 button to reset the device to standard parameters - "Reset"

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Fig.3 View of the upper part of PCE-HT 420 monitor
5. Operation
Afterwiring,mountingandpoweringthemonitorisreadyto
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 power is turned on the display shows the name of the device
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.
-restoringfactoryparameters -afterpressingandholdingthe
button for 10seconds;Note: each successiverestoration of factory
parametersenablesordisablestheserviceofobtainingnetwork
addressfromaDHCPserver,i.e.iftheDHCPserviceisenabled
andrestoringthefactoryparameterswillbeforced,theDHCP
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
assignedtothedevice:192.168.1.19(subnetmask:

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255.255.255.0),anotherrequestforrestoringthefactory
parameterswillenabletheDHCPserverservice-thenetwork
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 de ice – 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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fromaDHCPserveryoumustrestorethemonitortofactory
defaults,p.5.2,andrestartthedevice-thenyoushouldseethe
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.
Aftergainingaccesstothefullconfigurationwerecommend
thatyoudisabletheDHCPclient,leavingtheacquirednetwork
parametersunchanged–IP address,subnetmask,gateway,DNS
address will be stored as static parameters.
5.3.2. Connecting the monitor to the network without using
a DHCP server
InordertousetheautomaticconfigurationwithaDHCPserver,
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
displayedIPaddressisthecurrent
address of the monitor set manually or the default IP address (after
restoringthedefaultparameters),ifthedisplayedaddressis
differentfrom192.168.1.19thefactorydefaultsshouldberestored
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.

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Fig. Description of the monitor reading field
Tables 1, 2 show the symbols displayed on the LCD, and their
meanings. Table1
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
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 alocal 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. onnection 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 RJ4 slot pins
Description of the monitor RJ45 slot diodes function:
● yellowLED - 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.
● greenLED - 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.
Table 3
Conduct
or no. Signal Conductor color acc. to standard
EIA/TIA 568A EIA/TIA 568B
1 TX+ white-green white-orange
2 TX- green orange

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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
5.6.2. Ethernet interface default parameters
Table 4
No. Name Default value
1. DHCP Enabled or disabled
(cycled when default parameters
restoration is forced)
2. IPAddress 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
Changing the parameters of the Ethernet interface is possible
through the built-in web server.

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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).

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5.6.3.1 General view
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