Chapter 1: Introduction

This chapter provides basic information about the device. Before starting, please read this manual carefully.

The P2520 two-channel current loop converter is designed to connect sensors with output 0-20 mA or 4-20 mA into an Ethernet network. Current can be recalculated to a physical value measured by the connected sensor. Sensors can be powered directly from the P2520 Converter. The P2520 has two current inputs. These inputs are not galvanically isolated.

General Safety Rules

The following summary is used to reduce the risk of injury or damage to the device. To prevent injury, please follow instructions in this manual carefully.

• The device can be installed and repaired by a qualified person only. The device contains no serviceable parts inside.
• Do not use the device if it does not work correctly. Have the device checked by a qualified service person if you think that it is not working properly.
• It is forbidden to use the device without the cover. Inside the device, there can be dangerous voltage and a risk of electric shock.
• Use only an appropriate power supply adapter according to manufacturer specifications and approved according to relevant standards. Ensure that the adapter does not have damaged cables or covers.
• Connect the device to network parts approved according to relevant standards only.
• Connect and disconnect the device properly. Do not connect or disconnect the Ethernet cable or current inputs when the device is powered.
• Do not short-circuit power supply terminals +U1 and +U2 to the GND terminals.
• The device may be installed in prescribed areas only. Never expose the device to temperatures higher or lower than allowed. Protect the device from dripping or splashing water and do not use it in areas with condensation.
• Do not use the device in potentially explosive environments.
• Do not stress the device mechanically.

Device Description and Important Notices

This chapter contains information about basic features and device functional safety.

Values from the device can be read using an Ethernet connection. The following formats are supported:

• Web pages with XML and JSON files
• Modbus TCP protocol
• SNMPv1 protocol
• SOAP protocol

The device can also be used to check measured values, and if a limit is exceeded, the device sends warning messages. Possible ways of sending warning messages include:

• Sending e-mails to up to 3 e-mail addresses
• Sending SNMP traps to up to 3 configurable IP addresses
• Displaying the alarm status on the web page
• Sending messages to a Syslog server

Device setup can be performed via the web interface. The latest firmware version can be obtained from technical support. Do not upload firmware that is not designed for your device, as unsupported firmware can damage it.

⚠️ Reliability of warning messages (e-mail, trap, syslog) depends on the actual availability of necessary network services. The device should not be used for critical applications where a malfunction could cause injury or loss of human life. For highly reliable systems, redundancy is essential. For additional information, please see standard IEC 61508.

⚠️ Never connect the device directly to the Internet. If it is necessary to connect the device to the Internet, a properly configured firewall must be used. For remote connections, VPN or similar secured access should be used.

Chapter 2: Getting Started

Here you can find information necessary to put newly purchased equipment into operation. Read the information about current loop connection carefully.

What is Needed for Operation

To install the unit, you need the following equipment. Please check if it is available before installation:

• P2520 current loop converter
• Screwdriver for removing the cover
• Power supply - according to specification (commonly DC 24 V/1.0 A)
• RJ45 LAN connection with appropriate cable
• Free IP address in your network
• Sensor(s) with current loop output (4-20 mA or 0-20 mA)

Mounting the Device

• Check if the equipment from the previous chapter is available.
• Install the latest version of TSensor software. This software will help you find the device on the network and change its IP address. Device configuration is made using the web interface. TSensor software can be downloaded from the manufacturer's website.
• Contact your network administrator to obtain the following information for connection to the network:
  • IP address: ____________________
  • Gateway: ____________________
  • Netmask: ____________________
  • DNS IP address: ____________________

Check for IP address conflicts when connecting the device to the network for the first time. The device has a factory-set IP address of 192.168.1.213. This address must be changed according to the information from the previous point. When installing several new devices, connect them to the network one after another.

Remove the device cover, connect current loops, and power supply terminals according to the image below. Input channels on the device are not galvanically isolated. The power supply is also not isolated from the inputs. The device is isolated from the communication line side only. Carefully consider how to connect the sensor with current output into your P2520.

• Close the device cover.
• Connect the Ethernet connector.
• Power on the power supply adapter.
• LEDs on the LAN connector should blink after connecting the power.

P2520 Inputs Schematic:

[Diagram showing P2520 inputs with +U1, +I1, GND, +U2, +I2, GND, +Ucc, GND connected to internal circuitry with 20Ω resistors and a CPU, leading to an RJ45 connector.]

Sensor Connection Example:

Passive two-wire transmitter: [Diagram showing a transmitter with +U, -I, and shielding connected to the P2520 inputs +U, +I, and GND respectively.]

Active current source: [Diagram showing a source with Power, Iout, and GND connected to the P2520 inputs +U, +I, and GND respectively.]

Device Settings

• Run configuration software TSensor on your PC.
• Switch to an Ethernet communication interface.
• Press the button Find device....

Chapter 3: Device Setup

This chapter describes basic device configuration. There is a description of settings using the web interface.

Setup Using Web Interface

The web interface can be managed by a web browser. The main page will be shown when you insert the device address into the address bar of your web browser. There you will find actual measured values. A page with history graphs is shown when you click on the tile with actual values. Access to device setup is possible via the Settings tile.

[Screenshot showing the web interface of the device with sections for Humidity and Temperature, displaying values and alarm status, along with navigation tiles like History, .CSV, Mobile, Web, Settings, About.]

General Settings

Device name can be changed using the Device name item. Measured values are stored into memory according to the History storage interval field. After changing this interval, all history values will be cleared. Be aware that the content of memory for history values is not preserved after device restart or power loss. Changes must be confirmed by the Apply settings button.

Network Settings

Network parameters can be obtained automatically from a DHCP server using the option Obtain an IP address automatically. A static IP address can be configured via the IP address field. It is not necessary to set a Default gateway if the device is used within a single subnet. The DNS server IP is used for resolving addresses for SOAP protocol or communication with an SMTP (mail) server. The option Standard subnet mask sets the network mask automatically according to network class A, B, or C. The Subnet mask field must be set manually when a network with a non-standard range is used. The Periodic restart interval enables the device to restart after a selected time since device start.

Alarm Limits

For each measurement channel, it is possible to set upper and lower limits, a time-delay for alarm activation (0 – 30000 s), and hysteresis for alarm clearing.

[Diagram illustrating alarm limits, showing a graph with 'value' on the Y-axis and 'time' on the X-axis. It depicts a 'limit high', 'hysteresis', 'Time delay', and 'ALARM' state. Points 1 through 5 are marked on the time axis to explain the alarm activation and clearing process.]

In Point 1, the measured value exceeded the limit. From this time, the time-delay is counting. Because at point 2 the value dropped below the limit value before the time delay expired, the alarm was not set.

In Point 3, the value has risen over the limit again. During the time-delay, the value does not drop below the set limit, and therefore, at Point 4, an alarm was triggered. At this moment, e-mails were sent, traps were set, and the alarm flag was set on the website, SNMP, and Modbus.

The alarm lasted until Point 5, when the measured value dropped below the set hysteresis (high limit - hysteresis). At this moment, the active alarm was cleared, and an e-mail was sent.

When an alarm occurs, alarm messages will be sent. In case of power failure or device reset (e.g., changing the configuration), the new alarm state will be evaluated, and new alarm messages will be sent.

Channels

A channel can be enabled or disabled for measuring using the checkbox Enabled. A channel can be renamed, and its unit can be changed. Measured current is recalculated to a physical representation according to the selected linear equation. The number of decimal places is selectable. All changes must be confirmed using the Apply settings button. History values are cleared after changing channel settings.

SOAP Protocol

The SOAP protocol can be enabled by the option SOAP protocol enabled. The address of the destination HTTP server is configurable via the SOAP server address field. The option SOAP server port can be used for setting the destination server port. The device sends SOAP messages according to the selected Sending interval. The option Send SOAP message when alarm occurs sends a message when an alarm on a channel occurs or is cleared. These SOAP messages are sent asynchronously at the selected interval.

The SOAP protocol is used for data transfers into COMET Cloud or COMET Database. A detailed description of the setup can be found in the documentation for each data acquisition system.

Email Configuration

The Email sending enabled option allows email features. It is necessary to set the address of the SMTP server in the SMTP server address field. The default port of the SMTP server can be changed using the SMTP server port item. SMTP authentication can be enabled using the SMTP authentication option. When authentication is enabled, Username and Password must be set.

For successful email sending, it is necessary to insert an Email sender address. This address is usually the same as the username for SMTP authentication. In the fields Recipient 1 to Recipient 3, it is possible to set the addresses of email recipients. The option Short email enables sending emails in a short format, which is usable when you need to forward emails as SMS messages.

When the option Alarm email repeat sending interval is enabled and there is an active alarm on a channel, emails with actual values are sent repeatedly. The Info email sending interval option enables sending emails at a selected time interval. A CSV history file can be sent together with repeat/info emails. This feature can be enabled by the Alarm and Info emails attachment option.

It is possible to test the email function using the Apply and test button. This button saves the new setting and sends a testing email immediately.

Modbus and Syslog Protocols

ModbusTCP and Syslog protocol settings are configurable via the Protocols menu. Modbus server is enabled by default. Deactivation is possible via the Modbus server enabled option. The Modbus port can be changed via the Modbus port field. The Syslog protocol can be enabled using the Syslog enabled item. Syslog messages are sent to the IP address of the Syslog server, specified in the Syslog server IP address field.

SNMP

For reading values via SNMP, it is necessary to know the password - SNMP read community. SNMP Traps can be delivered to up to three IP addresses, specified in IP address of the Trap recipient. SNMP Traps are sent upon an alarm or error state on the channel. The Trap feature can be enabled by the option Trap enabled.

Time Synchronization

Time synchronization with an SNTP server can be enabled by the Time synchronization enabled option. The IP address of the SNTP server is necessary to set in the SNTP server IP address item. SNTP time is synchronized in UTC format, and it is necessary to set the corresponding time offset – GMT offset [min]. Time is synchronized every 24 hours by default. The option NTP synchronization every hour decreases this synchronization interval to one hour.

WWW and Security

Device security features can be enabled by the Security enabled option. When security is enabled, it is necessary to set an administrator password. This password will be required for device settings. If secured access is required even for actual value reading, it is possible to enable the User account only for viewing option. The port of the WWW server can be changed from the default value 80 using the WWW port field. Web pages with actual values are refreshed according to the Web refresh interval field.

Backup and Maintenance

Backup

Device configuration can be saved to a file. This file can be used for restoring configuration or cloning configuration between devices. Configuration can be cloned between the same device models only. It may restore all device settings with the exception of network settings, WWW, and security settings.

Factory Defaults

The Factory defaults button sets the device to factory configuration. Network parameters (IP address, Subnet mask, DNS, Gateway) are left unchanged.

Network parameters are changed when you press a button inside the device. For more information, please read the chapter Factory Defaults.

Factory parameters settings:

Chapter 4: Communication Protocols

Short introduction to communication protocols of the device. To use some communication protocols, necessary software is required, which can use the protocol. This software is not included.

Website

The device supports displaying of measured values, history graphs, and configuration using a web browser. History graphs are based on HTML5 canvas. The web browser must support this feature for proper function of graphs. Firefox, Opera, Chrome, or Edge can be used. If the device has IP address 192.168.1.213, type http://192.168.1.213 into your browser. Actual measured values can be obtained using the file values.xml or values.json. Values from history can be exported in CSV format. History storage interval can be set using the web interface. History is erased after every reboot of the device. Reboot of the device is performed when the power supply is disconnected and after some configuration changes.

SMTP – Sending E-mails

When measured values are over the set limits, the device allows sending an e-mail to a maximum of 3 addresses. An e-mail is sent when an alarm condition on the channel is cleared or a measuring error occurs. It is possible to set a repeat interval for email sending. For correct sending of emails, it is necessary to set the address of the SMTP server. SMTP authentication is supported, but SSL/TLS is not. The standard SMTP port 25 is used by default. The SMTP port can be changed. Contact your network administrator to obtain configuration parameters of your SMTP server. E-mails sent by the device cannot be answered.

SNMP

Using SNMP protocol, you can read actual measured values and alarm status. Writing via SNMP protocol is not supported. It supports SNMPv1 protocol version only. SNMP uses UDP port 161. OID keys description can be found in the MIB table, which can be obtained from the device website or your distributor. The password for reading is factory set to public.

OID Keys:

When an alarm occurs, warning messages (traps) can be sent to selected IP addresses. Addresses can be set using the web interface. Traps are sent via UDP protocol on port 162. The device can send the following traps:

Modbus TCP

The device supports Modbus protocol for communication with SCADA systems. The device uses Modbus TCP protocol. The TCP port is set to 502 by default. The port can be changed using the web interface. Only two Modbus clients can be connected to the device at one moment. The Modbus device address (Unit Identifier) can be arbitrary. Modbus write command is not supported. Specification and description of the Modbus protocol is free to download at: www.modbus.org.

Supported Modbus commands (functions):

Modbus device registers. Address could be 1 higher, depending on the type of communication library used:

Description:

• Int16b: registry range is -31999 to 32767, error value <= -32000
• Int16b*10: registry is in format integer*10 – 16 bits, 12.5dgrC = 125, error value <= -32000
• Int16b*100: registry is in format integer*100 – 16 bits, 12.53dgrC = 1253, error value <= -3200
• Float32b: two Modbus registers containing IEEE754 float, lower 16bits first, error value = -inf
• Int32b*100: two Modbus registers containing 32bit signed integer*100, 12.53dgrC = 1253, lower 16bits first, error value <= -320000000
• Ascii: two ASCII character in register
• BCD: registry is coded as BCD
• n/a: item is not defined, should be read

SOAP

The device allows you to send currently measured values via SOAP v1.1 protocol. The device sends values in XML format to the web server. The advantage of this protocol is that communication is initialized by the device side. Due to it, port forwarding is not necessary. If the SOAP message cannot be delivered, a warning message via SNMP Trap or Syslog protocol is sent. The file with the XSD schema can be downloaded from: http://cometsystem.cz/schemas/soapP2520.xsd. SOAP message example:

Host: 192.168.1.132
Content-Type: text/xml; charset=utf-8
Content-Length: 656
SOAPAction: "http://tempuri.org/InsertP2520Sample"

<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<soap:Body>
<InsertP2520Sample xmlns="http://cometsystem.cz/schemas/soapP2520.xsd">
<name>Current Loop Converter</name>
<sn>11940986</sn>
<tmr>60</tmr>
<kind>4357</kind>
<c1>
<n>Channel 1</n>
<v>3.25</v>
<f>00005040</f>
<u>mA</u>
<a>no</a>
<p>2</p>
<e>1</e>
</c1>
<c2>
<n>Channel 2</n>
<v>18.00</v>
<f>00009041</f>
<u>mA</u>
<a>no</a>
<p>2</p>
<e>0</e>
</c2>
</InsertP2520Sample>
</soap:Body>
</soap:Envelope>

XML and JSON

Measured values can be read from the HTTP server by HTTP GET requests. Values are available in two data formats: XML and JSON. Values can be obtained via files values.xml and values.json. The web server needs to be enabled for values to be available.

Example of values.xml file:

<root>
<err>0</err>
<devname>My device</devname>
<devsn>13940001</devsn>
<time>2021-04-06T07:48:44+01:00</time>
<timeunix>1617695324</timeunix>
<synch>1</synch>
<ch1>
<name>Humidity</name>
<unit>%RH</unit>
<aval>34.93</aval>
<alarm>1</alarm>
</ch1>
<ch2>
<name>Temperature</name>
<unit>C</unit>
<aval>22.31</aval>
<alarm>0</alarm>
</ch2>
</root>

Example of values.json file:

{
  "devname":"My device",
  "devsn":"13940001",
  "time":"07:58:32 2021-04-06",
  "timeunix":"1617695912",
  "synch":"1",
  "ch1":
  {
    "name":"Humidity",
    "unit":"%RH",
    "aval":"34.94",
    "alarm":1
  },
  "ch2":
  {
    "name":"Temperature",
    "unit":"C",
    "aval":"22.49",
    "alarm":0
  }
}

Syslog

The device allows sending text messages to a selected Syslog server. Events are sent using UDP protocol on port 514. Syslog protocol implementation is according to RFC5424 and RFC5426. Events when Syslog messages are sent:

SNTP

The device allows time synchronization with an NTP (SNTP) server. SNMP protocol version 3.0 is supported (RFC1305). Time synchronization is made every 24 hours. Time synchronization every hour can be enabled. For time synchronization, it is necessary to set the IP address of the SNTP server. It is also possible to set the GMT offset for the correct time zone. Time is used in graphs and history CSV files. The maximum jitter between two synchronizations of time is 90 seconds at a 24-hour interval.

Chapter 5: Troubleshooting

This chapter describes common problems with the P2520 and methods to fix these problems. Please read this chapter before calling technical support.

I Forgot the Device IP Address

The IP address is factory set to 192.168.1.213. If you have changed it and forgotten the new IP address, run the TSensor software and press Find device.... All available devices will be displayed in the window.

I Cannot Connect to the Device

In the search window, only the IP and MAC address are displayed. Other details are marked N/A. This problem occurs if the device's IP address is set to another network (subnet).

Select the device in the Find device window in TSensor software and press Change IP address. Follow the software instructions. To assign an IP address automatically using a DHCP server, set the device IP address to 0.0.0.0.

Device IP Address is Not Displayed in Window Find Device

In the TSensor software menu, press Help! My device was not found! in the Find device window. Follow the software instructions. The MAC address of the device can be found on the product label.

The Device is Not Found Even After Manually Setting MAC Address

This problem occurs especially when the IP address of the device belongs to another network and the Subnet mask or Gateway are incorrect. In this case, a DHCP server in the network is necessary. In TSensor software, press Help! My device was not found! in the Find device window. Set the new IP address to 0.0.0.0. Follow the software instructions. An alternative is to reset the device to factory defaults using the factory-defaults button.

Error Codes

The table below describes common error codes from the device:

I Forgot the Password for Setup

Please reset the device to factory defaults. The procedure is described at the following point.

Factory Defaults

This procedure restores the device to factory settings, including network parameters (IP address, Subnet mask, etc.). For factory defaults, follow these steps:

• Disconnect the power supply, unscrew the upper cover of the device case.
• Press the factory-defaults button and connect the power.
• Keep the button pressed for 10 sec.

[Image of the device showing a button labeled '0' and screw terminals.]

• Close the device.

Chapter 6: Technical Specifications

Information about technical specifications of the device.

Dimensions

[Diagram showing the dimensions of the device: 89 mm width, 76.5 mm mounting hole spacing, 40 mm depth, 73 mm height, with Ø4.3 mm holes for mounting.]

Basic Parameters

• Supply voltage: DC voltage from 9 V to 30 V
• Consumption: ~ 1 W device without powering connected sensors
• Protection: IP30
• Measuring interval: 1 sec; faster readings are available via Modbus TCP protocol. For more information, please contact technical support.
• Accuracy: ±0.1 %FS from 0 °C to +50 °C, ±0.3 %FS from -30 °C to +80 °C

Measuring Range:

0 to 25 mA

Resolution:

1 uA

A/D converter resolution:

24bit sigma-delta

Input Impedance:

20 Ω

Maximum overload current:

30 mA

Current load for +U1 and +U2 terminals:

max. 40 mA each. Terminals are connected to supply voltage via PTC thermistors (overload protection). Output voltage depends on actual current load; it is approximately about 1.2 V lower than supply voltage.

Communication port:

RJ45 connector – galvanically isolated from communication line, 10Base-T/100Base-TX Ethernet (Auto-Sensing)

Recommended Connector Cable:

For industrial use, a Cat5e STP cable is recommended. In less demanding applications, it can be replaced by a Cat5 cable, with a maximum cable length of 100 m.

Supported protocols:

TCP/IP, UDP/IP, ARP, ICMP, DHCP, HTTP, SMTP, SNMPv1, ModbusTCP, SNTP, XML, JSON, SOAPv1.1, Syslog

SMTP protocol:

SMTP authentication – AUTH LOGIN. Encryption (SSL/TLS/STARTTLS) is not supported.

Supported web browsers:

Mozilla Firefox 87 and later, Google Chrome 89 and later, Microsoft Edge 89 and later. The device should also be compatible with other browsers. Functionality was not tested with other web browsers.

Recommended minimum screen resolution:

1024 x 768

Memory:

1000 values for each channel inside non-backup RAM memory

Case material:

ASA

Mounting the device:

With two holes at the bottom of the unit

Weight:

~ 150 g

EMC:

2014/30/EU, EN 61326-1

Operating terms

Temperature and humidity range: -30 °C to +80 °C, 0 to 100 %RH (no condensation)

Working position: arbitrary

End of operation

Disconnect the device and dispose of it according to current legislation for dealing with electronic waste. Electronic devices must be professionally destroyed. ?

Technical support and service

Technical support and service is provided by the distributor. Contact information is included in the warranty certificate.

Preventive maintenance

Make sure the cables are not damaged periodically. The recommended calibration interval is 2 years.