Centrica Modbus TCP Manual

Panoramic Power
Modbus TCP Programmer’s Guide
Advanced 4th generation Bridge
Firmware v470 / August 2019

Contents
Introduction and overview......................................................................................................... 3
Hardware & Networking requirements...................................................................................... 4
Supported Hardware................................................................................................................................... 4
Supported LAN networks ............................................................................................................................ 4
Assigning a fixed bridge IP address............................................................................................................. 4
Bridge configuration.................................................................................................................................... 4
NTP requirements........................................................................................................................................ 4
Modbus parameters.................................................................................................................................... 5
Bridge Modbus Software Model ................................................................................................ 6
Modbus Register Map ................................................................................................................................. 6
Sensor slot allocation example ................................................................................................................... 7
Sensor Readings........................................................................................................................................... 8
Pulse counter registers................................................................................................................................ 9
Sensor Calibration keys .............................................................................................................. 9
Bridge Configuration for stand-alone mode............................................................................. 10
Connect to the bridge web interface ....................................................................................................... 10
Set networking mode ................................................................................................................................ 10
Set Connection mode................................................................................................................................ 10
Define bridge UI accessibility .................................................................................................................... 11
Assign sensors to slots............................................................................................................................... 12
View Sensor Readings................................................................................................................................ 13
Configure the bridge Pulse interface........................................................................................................ 14
Bridge led configuration for stand-alone mode ....................................................................... 14

Introduction and overview
This document covers the operation and interface definition of the Panoramic Power bridge when
working in the stand-alone mode. In this mode, the bridge implements a Modbus TCP protocol
which sends sensor’s current readings to a local server. The local server acts as a Modbus master
server and the bridge acts as a Modbus TCP slave.
This guide focuses on the new bridge stand-alone (Modbus TCP) operational mode. It is
supplementary to the Gen 4 Bridge User Guide which covers basic bridge operations and should be
reviewed prior to using this guide. We plan to merge these two guides in the future.
The image below depicts a typical network diagram for a bridge operating in the stand-alone
mode:
•Sensors transmit readings once every 10 seconds to the bridge via proprietary wireless
communications.
•For each configured sensor, the bridge stores the last received measurement in memory. It
will be stored until overridden by a new measurement from the same sensor or until the
bridge resets.
•A Modbus TCP master device (typically a computer or PLC) connects to the bridge via local
area network (LAN) and polls the bridges for sensor data.
•The Modbus master device can connect to multiple bridges, each of them receiving
multiple sensors.
•Bridge configuration is done via the bridge’s built in web server, using the web browser of
a laptop connected in the LAN.
Figure 1: Network diagram

Hardware & Networking requirements
Supported Hardware
•The Modbus TCP solution supports PAN10, PAN12 and PAN14 sensors only. PAN42 is not
supported.
•The Modbus TCP also support reading the bridge’s pulse inputs (Gen4 and above)
•The Modbus TCP solution is supported by every Gen3/Gen4/Gen4.5 bridge. Upgrading the
bridge firmware to the latest version (V.470 and above) is needed for the support of the
Modbus TCP interface.
•Each bridge supports up to 32 sensors in stand-alone mode
Supported LAN networks
To work in the Modbus TCP mode, the bridge has to be set-up for Ethernet or WiFi network
connectivity. A bridge configured for cellular network connectivity does not support Modbus TCP.
Assigning a fixed bridge IP address
For Modbus TCP to operate properly, the Modbus master must be able to repeatedly reach a
specific bridge via its IP address or DNS name. The solution requires a fixed IP address assigned for
the bridge. This can be done by selecting ‘fixed IP’ in the bridge network settings, or alternatively
using DHCP but ensuring that the DHCP server always assigns the same IP address to the specific
bridge.
Please refer to the Gen 4 Bridge User Guide for more information about configuring the bridge
networking.
Bridge configuration
Bridge configuration is done from a laptop’s web browser using the bridge built-in web server.
Initial bridge configuration, including setting up a fixed IP address to be used later, is done via a
directly connected laptop. Please see ‘Accessing the bridge web interface’ section in the Gen 4
Bridge User Guide.
One a fixed IP has been assigned to the bridge; further configuration can be done by navigating to
the bridge IP address from a web browser. The laptop used for such configuration must have HTTP
route to the bridge.
NTP requirements
In order to operate properly the bridge needs to get the real time clock (RTC). Since the bridge has
no battery-powered hardware RTC, it gets the time using a standard NTP server.
The bridge gets the NTP time, as part of the boot process, using the following process:
1. If a dedicated NTP server IP is defined, it will try to get the time from that server
2. Alternatively, it will try to get the time from a list of well-known public NTP servers
3. If both options above fail it will get the time from PowerRadar.
Option 3 above only works in ‘PowerRadar connected mode’or ‘combined mode’ (See ‘Connection
Setup’ section below). Therefore, when working in ‘Stand-Alone Modbus TCP’mode an NTP server
must be defined in the LAN or alternatively, NTP outbound access to public servers must be
implemented in the firewall.

Another option is to set the real-time clock via the Modbus Interface. This will override any time
retrieved during the boot process.
Modbus parameters
These parameters are needed when setting up the connection from the Modbus Master:
•The bridge Modbus interface is enabled via TCP port 502
•Recommended timeout value for the Master is 5 seconds

Bridge Modbus Software Model
Modbus Register Map
This section is for use by the Modbus Host programmer. The image below shows the bridge
register map as reflected to the Modbus Master:
Table 1 Bridge Register Map
Register #
(Dec)
Type
Functional
Code
Description
Size (16 bit
words)
Format
Comments
Bridge date/time
40001
40002
R/W
R- 4
W-16
Bridge date and time
(UNIX time)
2
UINT32
Set through Modbus or by NTP
Bridge information
30001
R
3
Bridge model
1
UINT16
0-GEN3, 1-GEN4, 2- GEN4.5
30002
30003
R
3
Bridge serial #
2
UINT32
Could be used as a test register
30004
R
3
Bridge mode
1
UINT16
1- Standalone, 2- Combined
30005
R
3
Bridge HW version
1
UINT16
30006
R
3
Bridge FW ver. - Major
1
UINT16
30007
R
3
Bridge FW ver. - Minor
1
UINT16
30008
R
3
Bridge Noise Floor [dBm]
1
INT16
30009-30010
R
3
Assigned slots
2
UINT32
Bit field format. One bit per slot.
1st slot in LSB.
1 –assigned slot, 0 - unassigned
Sensor Readings [Array of 32 slots]
32001+32N
R
3
Sensor status
1
UINT16
0-Slot Empty,
1-No message RX,
2- Message RX
3- Message RX , No RTC
32002+32N
32003+32N
R
3
Sensor S/N
(0: unassigned slot)
2
UINT32
N=Slot # (0-31)
32004+32N
R
3
Sensor Type
1
UINT16
10 -PAN10, 12-PAN12, 14- PAN14
32005+32N
32006+32N
R
3
Unix Epoc Timestamp
(0: RTC not set)
2
UINT32
N=Slot # (0-31)
32007+32N
32008+32N
R
3
Current Reading [A]
2
FLOAT32
N=Slot # (0-31)
32009+32N
R
3
Reading RSSI [dBm]
1
INT16
N=Slot # (0-31)
32010+32N -
32020+32N
R
3
Reserved for future use
11
N=Slot # (0-31)
Pulse Counter #1 Readings
35001
R
3
Status
1
UINT16
0-Disabled,
1-No pulse received since reboot
2-No RTC,
3- Pulse received since last reboot
35002-35003
R
3
Unix Epoc Timestamp
2
UINT32
(0: RTC not set)
35004-35005
R
3
Count (Pulse #1)
2
UINT32
Accumulated count during the
lifetime of the bridge
Pulse Counter #2 Readings
35006
R
3
Status
1
UINT16
0-Disabled,
1-No pulse received since reboot
2-No RTC,
3- Pulse received since reboot
35007-35008
R
3
Unix Epoc Timestamp
2
UINT32
(0: RTC not set)
35009-35010
R
3
Count (Pulse #2)
2
UINT32
Accumulated count during the
lifetime of the bridge

The map contains 5 main areas:
•Bridge date/time settings –This is where the Modbus host can set or read the Realtime
clock for the bridge. It can be used if there is no RTC server reachable by the bridge.
•Bridge information –Various bridge status data
•Sensor readings –An array of 32 slots. This is where the sensor readings are retrieved.
•Pulse Counter #1 and #2 Readings –These holds the counters for the two pulse inputs of
the bridge.
Sensor slot allocation example
The following image depicts an example of how the sensor software model works:
Figure 2: Software model example
In the example above:
•Only two of the 32 bridge slots have been assigned to sensors.
•Slot #1 has been assigned to sensor S/N 12345678
•Slot #2 has been assigned to sensor S/N 12312312
•Slots #3-#32 have not been assigned with any sensors and remain empty.
•Whenever a sensor message from one of the two sensors (12345678 or 12312312) is
received, the sensor-data section of the table will be updated. The update will override the
previous data.
•We can also see another sensor (S/N 55555555) which is received by the bridge but has
not been allocated to any slot. This sensor data will be ignored when the bridge is in
Modbus TCP mode.
In ‘PowerRadar connected mode’ or ‘combined mode’ all sensor data is simultaneously sent
to PowerRadar regardless of the assignment.

Sensor Readings
As seen in Figure 2 above, each sensor slot contains sensor data. This section will review and
explain the sensor data stored for each slot.
Figure 3 Sensor data storage
As seen in the image, each sensor slot reserve 40 bytes of memory and store the following values:
•Status –Indicating the status of the reading of the specific slot.
•Sensor S/N –This is the serial number of the sensor associated with this slot
•Timestamp –a UNIX Epoch timestamp of the latest message received from the bridge. It is
the number of seconds that have elapsed since 00:00:00 Thursday, 1 January 1970,
Coordinated Universal Time (UTC), minus leap seconds.
•Current [A] –The calibrated current (in A) measured in the last sensor message received.
•RSSI –an indication of the RSSI (signal strength) of the last measurement in dBm.
When reading the data, the status register should be analyzed first. Based on its content the other
registers should be processed as shown in the table:

Status
Code
Meaning
0
Slot Unassigned
This slot has no sensor S/N allocation. All other registers in
this slot can be ignored.
1
No Msg Received
A sensor S/N has been assigned to this slot, but no sensor
message has been received since the last bridge reset. This
can be because the sensor is not yet installed, is not in the
bridge RF coverage area or because the device monitored by
the sensor is off.
All other registers in this slot can be ignored.
2
Msg Received OK
A sensor S/N has been assigned to this slot, and a reading has
been received. The reading timestamp, Current value and
RSSI can be processed.
3
NO RTC
A sensor S/N has been assigned to this slot, and a reading has
been received. However, since the bridge has no real-time-
clock (RTC) the timestamp value is 0. In this case the Bridge
RTC clock should be set via the Bridge Date/Time settings
register.
Pulse counter registers
Gen 4 bridges (and above) support two pulse inputs. The bridge counts the pulses on each of the
inputs and provides this data in the registers.
Note: The bridge counts both rising and falling edges of the pulse. These registers store the total
count. This value is persistent even after bridge reset.
Sensor Calibration keys
Each Panoramic sensor is calibrated during manufacturing and a unique calibration key is
generated for every sensor. This key is used to calibrate the sensor raw measurements to achieve
optimal accuracy.
When working in PowerRadar mode, raw measurements are calibrated in the cloud. In stand-alone
mode, however, the calibration is done on the bridge itself, utilizing a unique calibration key.
The calibration key is a sensor specific, 15 alpha-numeric string (e.g. ACD43-XU3V5-Z7RF3), which
must be provided when allocating a sensor to be used in stand-alone mode and dual mode.
To get a calibration key for a specific sensor use one of the flowing options:
•Automatically calibration key retrieval - if the laptop used to configure the bridge has
Internet access, a calibration key can be automatically retrieved when defining the sensor
in the bridge. This is the easiest and most efficient way to get the calibration key. Internet
access is only required for the laptop used to set the bridge and only during the
configuration.
•Manual calibration key retrieval –In the rare case where internet access is not available
during bridge configuration, please contact [e-mail] with the
serial numbers of sensors needed. A file containing the respective calibration keys will be
provided to be manually entered into the bridge.

Bridge Configuration for stand-alone mode
To work in the stand alone-mode the bridge must be configured via the built-in web interface. This
is explained in detail in the Gen 4 Bridge User Guide.
Connect to the bridge web interface
Initial bridge configuration is done by forcing the bridge into configuration mode and directly
connecting a laptop with point-to-point ethernet cable.
The full process is defined in the ‘Accessing the bridge web interface’ section in the Gen 4 Bridge
User Guide.
Set networking mode
1. Navigate to the ‘Network Setup’ tab and set the bridge networking mode
2. Note that only ‘Ethernet’ and ‘Wi-Fi’ networks support the stand-alone mode
3. Set the IP configuration for the bridge. A static IP (or DHCP with fixed IP guarantee) must
be used in stand-alone mode to allow the master Modbus TCP to repeatedly address this
bridge.
Figure 4 The Network Setup Screen
Set Connection mode
1. Navigate to the ‘Connection Setup’ tab to set the bridge connection preferences.
2. By default, the bridge is configured to connect to PowerRadar
3. Check ‘Enable Stand Alone Modbus TCP’ to enable the Modbus TCP option.
4. Note that it is possible to set both ‘PowerRadar’ and ‘Modbus TCP’ modes concurrently. In
this case:
a. The bridge will send sensor data to PowerRadar (all received sensors)
b. In parallel, it will make sensor data available for Modbus TCP (allocated sensors
only)

Figure 5 The Connection Setup Screen
Define bridge UI accessibility
For enhanced security, the bridge UI is accessible by default only during configuration mode, using
a wired-connected laptop.
It is possible to change that configuration, making the UI accessible from any laptop in the same
LAN as the bridge. While less secure, this mode can be useful during testing and sensor setup when
multiple frequent changes are made to the bridge UI. Setting up a unique administrator password
is strongly recommended.
1. Navigate to the ‘Bridge Configuration’ tab
2. Choose bridge UI accessibility:
a. Choose ‘Only in config mode’ for maximum security –In this mode the bridge UI is
only accessible from laptop with direct Ethernet connection and only when the
bridge is placed in Configuration mode.
b. Choose ‘Always’ for maximum flexibility –In this mode the bridge UI is available
from any device with bridge network access. This mode is recommended only
during setup period and after a unique administrator password is set.
Figure 6 Bridge Configuration

Assign sensors to slots
Any sensor to be used by the Modbus interface must first be allocated to specific location (slot)
within the bridge. Once allocated, this sensor readings are guaranteed to always be in a fixed
register address.
Readings from sensors that were not assigned to a slot, will not be provided via the Modbus
interface (but will continue to be sent to PowerRadar if ‘Connect to PowerRadar’ is set in the
connection configuration page).
Assign a sensor to a slot
1. Navigate to the ‘Sensors’ tab
2. Choose an empty slot and press the ‘+’ icon
3. In the popup dialog:
a. Type the sensor serial number
b. Type the calibration key if you have it or click ‘Get calibration key’ to have it
automatically retrieved and inserted.
4. The sensor is now assigned to the slot. New readings will be shown in this screen and
made available via the Modbus TCP interface.
Figure 7 The Sensors Tab
Figure 8 Add Sensor Pop-up

Note 1: Stand-alone mode supports the following sensor types: PAN10, PAN12, PAN14. It
does not currently support PAN-42.
Note 2: The calibration key is a unique, per-sensor, value used by the bridge to calibrate
each reading for accuracy. It is a mandatory, sensor specific, value.
Note 3: When clicking ‘Get Key, your browser communicates with PowerRadar to get the
calibration key. It is, therefore, essential that the laptop has Internet connectivity.
Note 4: If having issues retrieving the calibration key, please contact support who can
provide an offline list of calibration keys to be entered manually.
View Sensor Readings
Sensor readings are available in the ‘Sensors Tab’. Each allocated sensor will display the last
received reading. A new reading will override the previous reading.
1. Navigate to the ‘Sensors’ tab. This Tab is only when ‘Connection Setup’ > ‘Enable Modbus
TCP’ is checked.
2. Allocated slots will show the following values:
a. Sensor S/N: The serial number of the allocated sensor
b. Current [A]: The last calibrated measurement in Ampere.
c. RSSI [dBm]: The received signal strength of the last measurement.
d. Timestamp: the time of last measurement.
Note 1: The information provided here is also available via the Modbus TCP interface.
Please refer to the Bridge Programmers Guide for more information.
Note 2: The current readings shown here have already been individually calibrated by the
bridge for accuracy, using the calibration key.
Note 3: PAN 10 and PAN 12 current readings can be used as-is. For PAN 14, these values
should be multiplied by the CT-Rate of the CT used.

Configure the bridge Pulse interface
1. Navigate to the ‘Pulse Setup’tab
2. Enable pulse input 1, 2 or both
3. Enabled pulses are made available for Modbus TCP base on the ‘Connection Setup’ >
‘Enable Modbus TCP’ value and are sent to PowerRadar based on the ‘Connection Setup’ >
‘Connect to PowerRadar’ value.
Figure 9 Pulse Setup Tab
Bridge led configuration for stand-alone mode
The bridge contains three hardware LED indicators that change based on bridge operations.
Fort a full list of led indication states, please refer to the Gen 4 Bridge User Guide. The information
below refers to changes in LED behavior in stand-alone mode.
In a ‘Standalone mode’ the bridge’s middle LED (network LED) supports the following behavior:
•Yellow blinking until local network connection (Ethernet or Wi-Fi) is established (same as in
‘PowerRadar’ mode).
•Green, 1-sec blink if local network connection is established but no Modbus connection
from a master device detected.
•Solid green when a Modbus master device connection is detected.
There is no change in LED behavior when in ‘PowerRadar’or ‘Combined’modes.