nextys DCW20 User Manual

DCW20 User Manual rev. 5

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DCW20

960W COMBO DC UPS / DC-DC

Converter

User Manual

POWERMASTER

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DISCLAIMER

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reserves the right to make changes without further notice to any products herein.

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makes no warranty, representation or guarantee regarding the suitability of its products for any
particular purpose, nor does

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assume any liability arising out of the application or use of any

product, and specifically disclaims any and all liability, including without limitation consequential or

incidental damages. “Typical" parameters which may be provided in

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data sheets and/or

specifications can and do vary in different applications and actual performance may vary overtime. All

operating parameters, including “Typicals", must be validated for each customer application by

customer's technical experts.

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does not convey any license under its patent rights nor the

rights of others.

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products are not designed, intended, or authorized for use as components in
systems intended for surgical implant into the body, or other applications intended to support or
sustain life, or for any other application in which the failure of the

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product could create a

situation where personal injury or death may occur. Should Buyer purchase or use

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products

for any such unintended or unauthorized application, Buyer shall indemnity and hold

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and its
officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs,
damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim
of personal injury or death associated with such unintended or unauthorized use, even if such claim
alleges that

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was negligent regarding the design or manufacture of the part.

The Customer should ensure that it has the most up to date version of the document by contacting its
local

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office. This document supersedes any earlier documentation relating to the products
referred to herein. The information contained in this document is current at the date of publication. It
may subsequently be updated, revised or withdrawn.

The Customer should ensure that

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product uses the most up to date Software and Firmware

provided on

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website to ensure reliable operation of the system.

All Trade Marks recognized. Specifications and information herein are Subject to change without
notice.

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1 Product description ........................................................................................................................................... 5

2 Features and benefits ....................................................................................................................................... 6

3 Functional description ...................................................................................................................................... 6

3.1 UPS mode .................................................................................................................................................. 7

3.1.1 Backup ................................................................................................................................................. 8

3.1.2 Battery health monitor .......................................................................................................................... 8

3.1.3 Battery charger ..................................................................................................................................... 9

3.1.4 Coulomb counter ................................................................................................................................ 10

3.1.5 PC shutdown and automatic restart ................................................................................................... 11

3.1.6 Cold start ............................................................................................................................................ 12

3.2 DC/DC mode ............................................................................................................................................ 12

3.2.1 Parallel operation ............................................................................................................................... 13

3.3 Current limit .............................................................................................................................................. 14

3.3.1 Current limit in UPS mode .................................................................................................................. 14

3.3.2 Current limit in DC/DC mode.............................................................................................................. 14

3.4 Inhibit ........................................................................................................................................................ 14

3.5 Modbus ..................................................................................................................................................... 15

4 User interface ................................................................................................................................................. 19

4.1 Status ........................................................................................................................................................ 20

4.2 Settings ..................................................................................................................................................... 20

4.2.1 Modbus address ................................................................................................................................. 21

4.2.2 Modbus baudrate ............................................................................................................................... 21

4.2.3 Modbus parity ..................................................................................................................................... 21

4.2.4 Modbus stop bits ................................................................................................................................ 21

4.2.5 Battery type ........................................................................................................................................ 21

4.2.6 Battery charge voltage ....................................................................................................................... 21

4.2.7 Battery charge current ........................................................................................................................ 21

4.2.8 Battery float voltage ........................................................................................................................... 22

4.2.9 Battery low voltage ............................................................................................................................. 22

4.2.10 Battery deep discharge voltage ...................................................................................................... 22

4.2.11 Battery max. discharge current ....................................................................................................... 22

4.2.12 Battery capacity - Supercap capacitance ....................................................................................... 22

4.2.13 Battery min. temperature ................................................................................................................ 22

4.2.14 Battery max. temperature ............................................................................................................... 22

4.2.15 Battery lifetime ................................................................................................................................ 23

4.2.16 Ri alarm mode ................................................................................................................................. 23

4.2.17 Ri nom. ............................................................................................................................................ 23

4.2.18 Ri max. variation ............................................................................................................................. 23

4.2.19 Operating mode .............................................................................................................................. 23

4.2.20 Nominal output voltage ................................................................................................................... 23

4.2.21 Max. input current ........................................................................................................................... 24

4.2.22 Max. output current ......................................................................................................................... 24

4.2.23 Max. Backup time enable ............................................................................................................... 24

4.2.24 Max. backup time ............................................................................................................................ 24

4.2.25 Buzzer enable ................................................................................................................................. 24

4.2.26 Relay 1 configuration ...................................................................................................................... 25

4.2.27 Relay 2 configuration ...................................................................................................................... 25

4.2.28 Inhibit polarity .................................................................................................................................. 25

4.2.29 DC/DC output mode ........................................................................................................................ 25

4.2.1 Output enable ..................................................................................................................................... 25

4.2.1 Aux enable ......................................................................................................................................... 26

4.2.2 PC shutdown enable .......................................................................................................................... 26

4.2.3 PC automatic restart enable............................................................................................................... 26

4.2.4 PC shutdown delay ............................................................................................................................ 26

4.2.5 PC shutdown time .............................................................................................................................. 26

4.2.6 PC restart minimum time .................................................................................................................... 26

4.2.7 PC off detection current threshold ..................................................................................................... 26

4.2.8 PC off detection timer ......................................................................................................................... 27

4.2.9 Battery installation date ...................................................................................................................... 27

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4.2.10 Battery charge cycles...................................................................................................................... 27

4.3 Info ............................................................................................................................................................ 27

4.3.1 Firmware version ................................................................................................................................ 27

4.3.2 Firmware subversion .......................................................................................................................... 27

4.3.3 Build date ........................................................................................................................................... 27

4.3.4 Build time............................................................................................................................................ 27

4.3.5 Serial number ..................................................................................................................................... 28

4.3.6 Boot cycles ......................................................................................................................................... 28

4.3.7 Operating time .................................................................................................................................... 28

4.3.8 Battery operating time ........................................................................................................................ 28

4.4 Logs .......................................................................................................................................................... 29

4.4.1 Info ..................................................................................................................................................... 29

4.4.2 Alarms ................................................................................................................................................ 30

4.4.3 Events ................................................................................................................................................ 34

4.5 Wizard ....................................................................................................................................................... 34

5 Technical Specifications ................................................................................................................................. 34

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1 Product description

Use latest device Documentation, Software and Firmware to ensure reliable operation of

the system (downloadable from www.nextys.com).

DCW20 is a microprocessor controlled unit that can perform 2 functions:

1. UPS rated 960W/20A usable in any system rated 12…48Vdc

2. DC/DC converter (non isolated) rated 960W/20A usable in any combination of IN/OUT
voltages 12…48Vdc

For the UPS function, it may use 1 battery of 12V, independently of the operating load voltage. For
any supply voltages (12…48Vdc) it may use also multiple battery configuration (10…58Vdc). DCW20
monitors the voltage coming from a DC power supply and in case of power failure a backup battery is
supplying the energy to the load. In normal condition the battery is kept charged by an integrated
battery charger supporting various battery chemistries.
As a DC/DC converter (no battery present) the input must be connected to the battery connector.
The input voltage is converted to any output voltage as per the set-up.

1. Alarm LED indicator: ON when the unit is in
backup. Blinks at 1Hz rate in case of error.

2. Modbus over USB: Used to connect a PC
running POWERMASTER or custom application
for remote monitoring and controlling. Firmware
update is also possible through USB
connection.

3. Temperature sensor: Optional temperature
sensor (P/N: WNTC-2MT) to measure the
battery temperature for protection and
temperature compensated charge method.

4. Relays dry contacts: 2 relays are present for
remote monitoring. See §4.2.26 for more
details.

5. Modbus over RS485: Used to connect a PC
running POWERMASTER or custom application
for remote monitoring and controlling. Firmware
update is also possible through RS485
connection.

6. Inhibit input: A voltage between 5VDC and
30VDC applied to this input activates the inhibit
function (§3.4).

7. Auxiliary output supply: Maximum 5A supply
from the battery (unregulated).

8. Input connection: 2 poles are provided for input connection. This must be connected to a
power supply rated 12…48VDC.

9. Output connection: 2 poles are provided for output connection. It must be connected to the
load to be backed up.

10. Battery connection: 2 poles are provided for battery connection. This must be connected to
the battery. Although the unit is protected, please respect the correct polarity.

11. Display area: provides information regarding the device status.

12. Control keys: 4 push buttons are provided to navigate through the menus and to select the
various functions.

Figure 1: Front panel view

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2 Features and benefits

The main features are:

 Integrated battery charger for 12…48V multi-chemistries batteries with a charging current up

to 20A

 Can be operated with SUPERCAP capacitors instead of batteries
 20 A or 960W rated load
 Automatic sensing of input voltage, load current and battery current
 Battery protection against reverse polarity connection and overcurrent
 Battery health monitoring system: measuring battery resistance, battery temperature,

charge/discharge cycles and Coulomb counter

 User settable maximum backup time
 Remote inhibit input
 Connection for a battery thermal sensor (optional)
 Modbus over USB and RS-485 interfaces for control and monitoring
 Auxiliary output from the battery voltage (max. 5A), protected against overcurrent/short circuit
 Suitable for energy management applications
 Suitable for POWERMASTER software (available for Windows and Android)

Embedded user interface:

 4 keys and 1 color graphic LCD display
 Allows online device configuration
 Displays the DCW20 status and alarms
 2 Dry contacts for programmable status signals

Free PC and Android application POWERMASTER used for:

 Connection through Modbus
 Remote monitoring and configuration
 Firmware upgrade
 Same functionalities of the embedded user interface with the ease of the PC benefits

3 Functional description

DCW20 is a high performance digitally controller DC-UPS that can be used in any DC system with a
rated voltage between 12V and 48V and up to 20A.
At the core of the device a bidirectional DC/DC buck-boost converter (see Figure 2) acts as a battery
charger when the input supply is present. In case of a power outage (backup) the converter keeps the
output voltage regulated draining power from the battery. The converter is digitally controlled.

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Input

Input

switch

I

U

Input voltage

and current

measurement

I

U

Output voltage

and current

measurement

Output

I

U

Battery voltage

and current

measurement

I

U

Auxiliary volt age

and current

measurement

Auxiliary

supply

Battery

30A

Fuse

DC

DC

Bidirectional

digital control

DC/DC

converter

Battery
reverse

polarity

protection

Digit al

fuse

uController

Power path

Monitoring and control

Battery healt h

monitor

Modbus/RTU

USB
RS485

I/O

2xRelays
Inhibit

HMI

Figure 2: DCW20 simplified block diagram

3.1 UPS mode

In UPS mode the DCW20 protects a
load from unwanted power interruption
in case of mains failure. An example of
UPS connection is given on Figure 3.
When the input is present DCW20 acts
as a bypass, connecting the input to the
output via the input switch. Meanwhile, if
required, the battery is charged. During
bypass there is no voltage conversion,
therefore the output supply voltage is
equal to the input voltage.
In case of power outage, the DCW20
takes energy from the battery to keep
the output regulated at “Nominal output
voltage” (§4.2.20).
¨

Figure 3: UPS connection example

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3.1.1 Backup

The system is in backup mode if the supply for the output is sourced from the battery (input supply
missing). During backup the battery is monitored continuously to prevent over discharge.
A programmable backup timer (§4.2.24) is also implemented in order to fix a maximum backup time
during power outages. This allows preserving the battery life and shortening the recharge time,
avoiding discharging the battery when not needed.
During backup the internal Coulomb counter is used to give an estimation of the residual charge of
the battery.
Backup starts when the output voltage is lower than 90% of the “Nominal output voltage” (§4.2.20).

3.1.2 Battery health monitor

The battery health monitor is composed of:

 Internal resistance measurement: The resistance is periodically measured. The internal

resistance is a good indicator of the battery health status; a sudden increase of the internal
resistance indicates a potential problem on the battery or on the battery wiring.

 Temperature measurement: The battery temperature is monitored through an optional

temperature sensor (P/N: WNTC-2MT). The battery charger takes into account the battery
temperature and provides a temperature compensated charging voltage. In case of over or
under temperature the system disconnects the battery to prevent damage.

 Coulomb counter: Estimates the remaining battery capacity and consequently the

available backup time.

 Deep discharge protection: It protects against the deep discharge of the battery which

can lead to its irreversible damage.

The battery internal resistance (Ri) is measured by draining a defined AC current through an active
load (AL) from the battery and measuring the AC voltage drop across the load terminals. The principle
is represented in Figure 4.

AC active

load (AL)

Battery

Ri

+

Rcables

Iac

Rcon

Uac

Figure 4: Internal resistance measurement

The measured resistance is the sum of the battery internal resistance, the cables resistance and the
connectors resistance, therefore cabling problem such as loose connectors are also detected with Ri

measurement.
When high capacity batteries and/or small and long cables are used R

cables+Rcon

may be > Ri.

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3.1.3 Battery charger

The battery charger supports various chemistries such Lead-Acid, Nickel, Lithium and
Supercapacitors. The charging algorithm for each chemistry is given below. Other charging algorithms
can be implemented by request (contact factory).
The battery charger automatically reduces the current to avoid exceeding the maximum input current
(§4.2.21) in case of high current load.

The user must set the following parameters to allow the charger to perform correctly:

 Battery type (§4.2.5).
 Battery charge voltage (§4.2.6)
 Battery charge current (§4.2.7)
 Battery float voltage (§4.2.8)

The battery charge terminates in case at least one of the following conditions are satisfied:

 Low current: The measured battery charge current is lower than 10% of the “Battery

charge current” while the measured voltage is at least 98% of the “Battery charge voltage”.

 Timer: the charge is terminated after the battery has been charged for a predetermined

amount of time. The value is automatically calculated by the device.

For Nickel batteries only, the following conditions are also checked:

 Temperature Cutoff (TCO): The battery temperature if higher than the “Battery maximal

temperature” (§4.2.14) minus 3°C for more than one minute. For example, if the maximal

battery temperature is set to 60°C, the charge terminates in case the temperature is higher
than 57°C.

 Rate of Temperature Increase (ΔT/dt): The battery temperature is rising at a rate equal or

superior to 1°C/min. To avoid unattended end of charge do not place the system on an
ambient with rapid changes of temperature (for example exposed to direct sunlight).

The charger voltage is independent on the input voltage (power supply), and is user settable.
Lead acid and lithium batteries share the same 3 stages charging algorithm as shown on Figure 5.

Time

Current

Voltage

Constant current

Constant voltage

Maintenance

Charge current

Charge voltage

Float voltage

Figure 5: Lead acid and Lithium charging algorithm

For nickel batteries, during maintenance, the DCW20 gives pulses of 3s every 30s with a maximum
current of 1/10 of “Battery charge current” and maximum voltage equal to “Battery charge voltage”.

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Time

Current

Voltage

Constant current

Constant voltage

Maintenance

Charge current

Charge voltage

Figure 6: Nickel charging algorithm

For Supercapacitor after the constant current phase the algorithm goes directly to maintenance
keeping the voltage at “Battery charge voltage”.

Time

Current

Voltage

Constant current

Maintenance

Charge current

Charge voltage

Figure 7: Supercapacitors charging algorithm

Warning: In order to avoid potentially hazardous situations including fire hazard, safety

recommendations must be followed. Only authorized staff can install the unit.

Warning: For Lithium cells the balancing and protection circuit must be included in the

battery pack.

For Nickel batteries the use of the external temperature sensor is mandatory. The sensor

must be placed in contact with the battery.

3.1.4 Coulomb counter

DCW20 measures the current flowing from / to the battery to keep track of the capacity available on
the battery. The capacity is measured in Ampere Hour [Ah]. The value shown is based on the
following assumptions:

 The value shown is just informative and does not represent the real state of charge of the

battery in some circumstances, for example if the battery is damaged.

 When the battery is connected for the first time or the system starts from OFF, the system

assumes the battery is fully discharged and start with 0Ah counter.

 Once the battery is fully charged the system sets the counter to the nominal capacity

specified by the user (§4.2.12).

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3.1.5 PC shutdown and automatic restart

PC shutdown: In case the DCW20 is used to supply a PC it is possible to automatically shut down

the PC after an adjustable time of backup. For this the PC must run the POWERMASTER application
(provided free) and must be connected through Modbus. Optionally POWERMASTER can call a task
on the PC before shutting down, for example to backup some sensitive data.
Automatic restart: DCW20 is able to automatically restart a PC which was powered OFF by mistake,
for example in case of the Operating System (OS) crash. The user may adjust an output current
threshold and a timer used for detecting the PC OFF status. In order to restart the PC the DCW20
toggles the output OFF and then ON again. User must enable in the PC BIOS the automatic start in
case of supply ON.

The diagram below shows the DCW20 behavior when Shutdown and automatic restart is enabled.

Time

PC OFF signal

PC status

Output voltage

Output current

Input voltage

T1 T2 T3

... ...

T4 T3

E3

E1

E2

E4

Ioff

Figure 8: Shutdown and restart chart

Parameter

Name

Description

E1

Backup

Power failure on the line happens. System enters backup
mode.

E2

Automatic PC
shutdown

The POWERMASTER sends a shutdown command to the PC.
Optionally: a task is called before shutdown.

E3

Unexpected PC
shutdown

The PC shutdowns in an unexpected way, for example caused
by OS crash.

E4

PC restart

DCW20 detects the PC being OFF because the output current
was lower than Ioff current threshold for T4 time. As a
consequence, DCW20 generates an ON->OFF->ON cycle on
its output.

T1

PC shutdown delay

User settable (§4.2.4). Time between start of backup and start
of PC shutdown procedure.

T2

PC shutdown time

User settable (§4.2.5). Time between start of shutdown
procedure and output voltage OFF. This time must be set
longer than the maximum time the PC takes to complete the

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shutdown.

T3

PC restart minimum

OFF time

User settable (§4.2.6). T3 is the delay used between the return
of the input voltage and the activation of the output. The same
time is used by the automatic restart function as power OFF
time to restart the PC. The value must be big enough for the
PC to detect the supply ON->OFF->ON cycle to restart.

T4

PC OFF detection
timer

User settable (§4.2.8). Minimum time at which the output
current must be below the Ioff current threshold to trigger the
automatic PC restart (PC supply ON->OFF->ON cycle).

Ioff

PC OFF detection
current threshold

User settable (§4.2.7). Current threshold used to detect PC
OFF status. This value must be lower than the minimum PC
current consumption when this is ON.

Table 1: Shutdown and restart

The parameters are settable through the DCW20 user interface or using the POWERMASTER
application. The checkbox “Run on startup” must be checked on POWERMASTER when PC shutdown
function is used. To inhibit the software from calling the shutdown command user can select the
“Inhibit shutdown” check box.

3.1.6 Cold start

The cold start is a procedure that allows turning ON the UPS without the input power. This procedure
is used to turn ON the UPS to operate during a power interruption. This practice is also a method to
see if the battery connected to the DCW20 is functional.
In cold start the DCW20 will remain ON for at least 60 seconds independently from the battery voltage
(even when being under the deep discharge threshold), the inhibit input and the backup timer.
After the first 60 seconds the device stays ON until the battery is not deep discharged, the backup
timer is not expired or the inhibit input is not active.
If the input supply returns during cold start the device reverts to normal operation.
To cold start the DCW20:

 Press and hold simultaneously the and buttons until you see the welcome message

on the screen. On the status screen the "Cold start” text is written beside the input icon.

 Release the buttons.

3.2 DC/DC mode

DCW20 can be used as a high
performance DC/DC converter. An
example of DC/DC connection is given
on Figure 9.
Any voltage between 10V to 55V can be
converted to any voltage between 10V
to 55V (step-up and step-down
operation) with up to 20A input or output
current.
Input and output are protected against
over current with user settable limits
(§3.3).
When used as a DC/DC converter the
input supply must be connected to the
battery connector as shown on Figure 9.

Figure 9: DC/DC connection example

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3.2.1 Parallel operation

When configured as DC/DC converter
multiple DCW20 can be connected with
output in parallel for power increase or
redundancy.
In this mode of operation, the field

“DC/DC output mode” (§4.2.29) must be
set to “Parallel”.

In case of parallel for redundancy an
external ORing module (for example
OR50) is required.
For proper operation between the 2
units the cable length connecting the 2
DCW20 to the load must have the same
length and cross-section.
For optimal current sharing it may be
necessary to slightly adjust one of the 2
devices output voltage until the same
current is delivered by the 2 units.
It is recommended to limit the load
power to 80% of the sum of the
individual output power of the paralleled
units.

Parallel connection for power increase of multiple DCW20 units is not recommended in

UPS mode. Contact factory for details.

Figure 10: DC/DC parallel connection example with

External redundancy module

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3.3 Current limit

DCW20 has the ability to limit the current flowing through its input, output and battery terminals to a
user settable threshold.

3.3.1 Current limit in UPS mode

In UPS mode DCW20 provides 3 different settings for the current limit:

 Maximum input current (§4.2.21), default 20A: it is used to limit the input current at a

specified threshold. For example if the DC power supply is rated less than 20A the threshold
can be lowered to avoid too high current drain from the power supply. When the input current
limit is reached the battery charging current is limited; if the input current can not be kept below
the threshold due to excessive loading an input overcurrent alarm is triggered. When the input
current is approaching the threshold, the measured input current is displayed with red fonts on
the LCD.

 Maximum output current (§4.2.22), default 20A: it is used to limit the maximum current

delivered to the load. When the threshold is reached due to excessive loading an output
overcurrent alarm is triggered. When the output current is approaching the threshold, the
measured output current is displayed with red fonts on the LCD.

 Battery maximum discharge current (§4.2.11), default 20A: it is used to limit the maximum

discharge current delivered from the battery during the backup function. When the threshold is
reached due to excessive loading a battery overcurrent alarm is triggered and the output
voltage starts to decrease. When the battery discharge current is approaching the threshold,
the measured battery current is displayed with red fonts on the LCD.

3.3.2 Current limit in DC/DC mode

In DC/DC mode DCW20 provides 2 different settings for the current limit:

 Maximum input current (§4.2.21), default 20A: it is used to limit the input current at a

specified threshold. For example if the DC power supply is rated less than 20A the threshold
can be lowered to avoid too high current drain from the power supply. When the input current
limit is reached due to excessive loading an input overcurrent alarm is triggered. When the
input current is approaching the threshold, the measured input current is displayed with red
fonts on the LCD.

 Maximum output current (§4.2.22), default 20A: it is used to limit the maximum current

delivered to the load. When the threshold is reached due to excessive loading an output
overcurrent alarm is triggered and the output voltage starts to decrease. When the output
current is approaching the threshold, the measured output current is displayed with red fonts on
the LCD.

3.4 Inhibit

An opto-isolated input allows the inhibition of the backup function in UPS mode or switching off the
output on DC/DC mode. The polarity of the input can be defined using the “Inhibit polarity” field
(§4.2.28).

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3.5 Modbus

DCW20 communicates through Modbus/RTU as specified on “MODBUS over Serial Line” and
“MODBUS APPLICATION PROTOCOL SPECIFICATION” documents available on

http://www.modbus.org/.

Table 2 contains the field types and Table 3 the mapped fields. For types bigger then 16bit, access all
registers in one transaction (multiple register read or write) to ensure atomic operation.

Type
Modbus
function codes

Description
Read

Write

BIT

1,2

5,15

Single bit with value 0 or 1

SINT16

3,4

6,16

Signed 16 bit value (2’s complement)

UINT16

3,4

6,16

Unsigned 16 bit value

SINT32

3

16

Signed 32 bit value (2’s complement) Composed of 2 consecutive
registers in big-endian order.

UINT32

3

16

Unsigned 32 bit value. Composed of 2 consecutive registers in big­endian order.

DATE

3

16

Time and date field. Composed of 4 Modbus registers as follows:

Address offset

Byte

Description

0
MSB

Reserved, set to 0

LSB

Year-2000

1
MSB

Month (1=January)

LSB

Day of the month

2
MSB

Hour of the day (24h format)

LSB

Minutes

3
MSB

Milliseconds
LSB

Table 2: Modbus types

Address

Type

R/W

Unit

Min.

Max.

Description

Common

0x0010

DATE

R/W

R/W

Real time clock.

Settings (see §4.2)

0x1000

UINT16

R/W

1 1 247

Modbus address.

0x1001

UINT16

R/W

1 1 5

Modbus baudrate.
1: 9600 baud
2: 19200 baud
3: 38400 baud
4: 57600 baud
5: 115200 baud

0x1002

UINT16

R/W

1 1 3

Modbus parity.
1: None
2: Even
3: Odd

0x1003

UINT16

R/W

1 1 2

Modbus stop bits.

0x1010

UINT16

R/W

1 1 4

Battery type.
1: Lead
2: Nickel

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Address

Type

R/W

Unit

Min.

Max.

Description

3: Lithium
4: Supercapacitor

0x1011

UINT16

R/W

0.1V

10

58

Battery charge voltage.

0x1012

UINT16

R/W

0.1A

0.5

20

Battery charge current.

0x1013

UINT16

R/W

0.1V

10

58

Battery float voltage.

0x1014

UINT16

R/W

0.1V

5

58

Battery low voltage.

0x1015

UINT16

R/W

0.1V

5

58

Battery deep discharge voltage.

0x1016

UINT16

R/W

0.1A

5

21

Battery max. discharge current.

0x1017

UINT16

R/W

0.1Ah

1

200

Battery capacity - Supercap
capacitance.

0x1018

SINT16

R/W

1°C

-40

60

Battery min. temperature.

0x1019

SINT16

R/W

1°C

-40

60

Battery max. temperature.

0x101A

UINT16

R/W

1kh 1 100

Battery lifetime.

0x101B

UINT16

R/W

1 0 3

Ri alarm mode.
0: Disabled
1: Fix
2: Automatic
3: Automatic done

0x101C

UINT16

R/W

0.1mΩ

0

300

Ri nom.

0x101D

UINT16

R/W

1%

50

300

Ri max. variation.

0x1020

UINT16

R/W

1 1 2

Operating mode.
1: UPS
2: DC/DC

0x1021

UINT16

R/W

0.1

10

58

Nominal output voltage.

0x1022

UINT16

R/W

0.1 5 21

Max. input current.

0x1023

UINT16

R/W

0.1 1 21

Max. output current.

0x1024

UINT16

R/W

1 0 1

Max. Backup time enable.
0: Disabled
1: Enabled

0x1025

UINT16

R/W

1m 1 1440

Max. backup time.

0x1026

UINT16

R/W

1 0 1

Buzzer enable.
0: Disabled
1: Enabled

0x1027

UINT16

R/W

1 0 65535

Relay 1 configuration (see §4.2.26).

0x1028

UINT16

R/W

1 0 65535

Relay 2 configuration (see §4.2.27).

0x1029

UINT16

R/W

1 1 2

Inhibit polarity.
1: Low
2: High

0x102A

UINT16

R/W

1 1 2

DC/DC output mode.
1: Single
2: Parallel

0x102B

UINT16

R/W

1 0 1

Output enable.
0: Disabled
1: Enabled

0x102C

UINT16

R/W

1 0 1

Aux enable.
0: Disabled
1: Enabled

0x1030

UINT16

R/W

1 0 1

PC shutdown enable.
0: Disabled
1: Enabled

0x1031

UINT16

R/W

1 0 1

PC automatic restart enable.
0: Disabled

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Address

Type

R/W

Unit

Min.

Max.

Description

1: Enabled

0x1032

UINT16

R/W

1s 1 3600

PC shutdown delay.

0x1033

UINT16

R/W

1s 1 600

PC shutdown time.

0x1034

UINT16

R/W

1s 1 60

PC restart minimum time.

0x1035

UINT16

R/W

0.1A

0

20

PC off detection current threshold.

0x1036

UINT16

R/W

1s 1 60

PC off detection timer.

0x1100

DATE

R/W

1 0 1

Battery installation date

0x1104

UINT16

R/W

1 0 65535

Battery charge cycles

Metering

0x2000

SINT16

R

0.1V

0

60

Input voltage.

0x2001

SINT16

R

0.1A

0

40

Input current

0x2002

SINT16

R

0.1V

0

60

Output voltage.

0x2003

SINT16

R

0.1A

0

40

Output current.

0x2004

SINT16

R

0.1V

0

60

Battery voltage.

0x2005

SINT16

R

0.1A

-25

25

Battery current.

0x2006

SINT16

R

0.1V

0

60

Auxiliary voltage.

0x2007

SINT16

R

0.1A

0

20

Auxiliary current.

0x2008

SINT16

R

0.1°C

-40

85

External temperature.

0x2009

SINT16

R

0.1mΩ

0

3000

Battery internal resistance.

0x200A

SINT16

R

0.1%

0

100

Battery charge percent.

0x200B

SINT16

R

0.1Ah

0

10000

Battery charge capacity.

0x2010

UINT16

R

1cycle

0

65535

Boot cycles.

0x2020

UINT32

R

1h 0 500000

Operating time.

0x2022

UINT32

R

1h 0 500000

Battery operating time.

Commands

0x3000

BIT W 1 0 1

Perform Ri measurement.

0x3001

BIT W 1 0 1

Shutdown.

0x3002

BIT W 1 0 1

Reset device.

State (see §4.4)

0x4000

BIT R 1 0 1

Battery charging.

0x4001

BIT R 1 0 1

Battery floating.

0x4002

BIT R 1 0 1

Battery discharging.

0x4010

BIT R 1 0 1

Battery disconnected.

0x4011

BIT R 1 0 1

Battery Ri too high.

0x4012

BIT R 1 0 1

Battery under temperature.

0x4013

BIT R 1 0 1

Battery over temperature.

0x4014

BIT R 1 0 1

Battery lifetime elapsed.

0x4015

BIT R 1 0 1

Battery charge failure.

0x4016

BIT R 1 0 1

Battery SoC < 25%.

0x4017

BIT R 1 0 1

Battery over discharge current.

0x4018

BIT R 1 0 1

Battery low.

0x4019

BIT R 1 0 1

Battery deep discharged.

0x4020

BIT R 1 0 1

USB powered.

0x4021

BIT R 1 0 1

Cold start.

0x4022

BIT R 1 0 1

PC shutdown.

0x4023

BIT R 1 0 1

PC power off.

0x4024

BIT R 1 0 1

External temperature sensor presence.

0x4025

BIT R 1 0 1

Inhibit.

0x4026

BIT R 1 0 1

Output disabled.

0x4027

BIT R 1 0 1

Auxiliary output disabled.

0x4030

BIT R 1 0 1

Backup.

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Address

Type

R/W

Unit

Min.

Max.

Description

0x4031

BIT R 1 0 1

Input under voltage.

0x4032

BIT R 1 0 1

Input over voltage.

0x4033

BIT R 1 0 1

Output under voltage.

0x4034

BIT R 1 0 1

Output over voltage.

0x4035

BIT R 1 0 1

Output overload.

0x4036

BIT R 1 0 1

Input over current.

0x4037

BIT R 1 0 1

Auxiliary output overload.

0x4038

BIT R 1 0 1

External temperature sensor error.

0x4039

BIT R 1 0 1

Backup time left < 25%.

0x403A

BIT R 1 0 1

Warning over temperature.

0x403B

BIT R 1 0 1

Error over temperature.

Table 3: Modbus fields

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4 User interface

Power ON screen:

This screen is shown at power ON. It shows the
device name, serial number and firmware version.

1s

1s

1s

1s

1s

3s

Status:

This is the default view where the user can find the
most relevant information about the device status.
The system always falls back to this view after 60s of
inactivity (no key pressed).

Settings:

All the device settings are configurable from this
menu. Use the UP/DOWN KEY to navigate through
the parameters. Press the OK KEY to enter/exit the
editing mode. In editing mode use the UP/DOWN
KEY to change the highlighted value.

Info:

Device information such as firmware version, serial
number and device name is visible from this menu.

Logs:

All the alarms and event are logged in a circular
buffer and visible from this screen. Use the
UP/DOWN KEY to navigate through the logs.

Wizard:

The wizard helps the user to configure the system
through a series of screens.

Table 4: User interface layout

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Symbol

Name

Function

MENU KEY

Scrolls between menus.

DOWN KEY

Scrolls down menus and values.

UP KEY

Scrolls up menus and values.

OK KEY

Confirms selection.

Table 5: User interface key

4.1 Status

The status screen shows the measurement and statuses to ease the system diagnostic. The screen is
divided in sections identified by the symbols shown below:

Input: The measured input voltage and current is shown in this section.

Output: The measured output voltage and current is shown in this section.

Battery: The battery voltage, current, temperature, resistance and charge are shown in this

section. During charging and discharging the symbol background color changes to orange and
the number of bars drawn inside reflects the charge status. During discharging and charging
an arrow drawn beside the symbol reflects the direction of the current flowing through the
battery, pointing towards the battery during charging. Battery section is not present in DC/DC
mode.

Auxiliary: The measured auxiliary output voltage and current is shown in this section.

For each section the icon background color reflects its status, green on healthy state or red/orange
otherwise.
Furthermore, in case of alarm a message appears on the screen after 60s of inactivity (no key
pressed).

Figure 11: UPS status screen

Figure 12: DC/DC status screen

Figure 13: Alarm screen

4.2 Settings

The setting menu contains all the configurable parameters available to the user. Use the UP/DOWN
KEY to navigate through the menu items. Press the OK KEY to enter and exit the editing mode,
exiting the edit mode stores and activates the new configuration. While in editing mode use the
UP/DOWN KEY to change the selected value. All settings are also accessible via Modbus at the
specified address. All the battery related settings are ignored in DC/DC operating mode.

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4.2.1 Modbus address

Default value

Range

Resolution

1

1…247

1

Unit

LCD name

Modbus address

NA

Modbus address

0x1000

The Modbus slave address for the device. The same address is used for USB and RS485 connection.

4.2.2 Modbus baudrate

Default value

Values (Modbus value)

38400

9600 (1), 19200 (2), 38400 (3), 57600 (4), 115200 (5)

Unit

LCD name

Modbus address

NA

Modbus baudrate

0x1001

The baudrate for Modbus over RS485 serial port.

4.2.3 Modbus parity

Default value

Values (Modbus value)

Even

None (1), Even (2), Odd (3)

Unit

LCD name

Modbus address

NA

Modbus parity

0x1002

The parity for Modbus over RS485 serial port. Available values are None, Even, Odd.

4.2.4 Modbus stop bits

Default value

Range

Resolution

1

1, 2

1

Unit

LCD name

Modbus address

NA

Modbus stop bits

0x1003

The parity for Modbus over RS485 serial port.

4.2.5 Battery type

Default value

Values (Modbus value)

Pb

Lead (1), Nickel (2), Lithium (3), SuperCap (4)

Unit

LCD name

Modbus address

NA

Bat. type

0x1010

Defines the type of battery connected to the device. See §3.1.3 for details about the different charging
algorithms.

4.2.6 Battery charge voltage

Default value

Range

Resolution

10V

10…58V

0.1V

Unit

LCD name

Modbus address

Volts

Bat. charge U

0x1011

The maximum voltage applied to the battery while charging. See §3.1.3 for details about the use of
this parameter on the different charging algorithms.

4.2.7 Battery charge current

Default value

Range

Resolution

0.5A

0.5…20A

0.1A

Unit

LCD name

Modbus address

Amperes

Bat. charge I

0x1012

The maximum current sourced to the battery while charging. See §3.1.3 for details about the use of
this parameter on the different charging algorithms.

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4.2.8 Battery float voltage

Default value

Range

Resolution

10V

10…58V

0.1V

Unit

LCD name

Modbus address

Volts

Bat. float U

0x1013

The maximum voltage applied to the battery once it’s fully charged. See §3.1.3 for details about the
use of this parameter on the different charging algorithms.

4.2.9 Battery low voltage

Default value

Range

Resolution

5V

5…58V

0.1V

Unit

LCD name

Modbus address

Volts

Bat. low U

0x1014

Threshold for “Battery low” alarm (§4.4.2.9).

4.2.10 Battery deep discharge voltage

Default value

Range

Resolution

5V

5…58V

0.1V

Unit

LCD name

Modbus address

Volts

Bat. deep disch. U

0x1015

Threshold for the “Battery deep discharged” alarm (§4.4.2.10).

4.2.11 Battery max. discharge current

Default value

Range

Resolution

21A

5…21A

0.1A

Unit

LCD name

Modbus address

Amperes

Bat. max. disch. I

0x1016

During backup the DCW20 limits the maximum discharge current to this value reducing the output
voltage if necessary.

4.2.12 Battery capacity - Supercap capacitance

Default value

Range

Resolution

1Ah or 1F

1…200Ah or F

0.1Ah or F

Unit

LCD name

Modbus address

Ampere hours or Farad

Bat. capacity

0x1017

Nominal capacity (Ah) of the installed battery or capacitance (F) in case a Supercapacitor is installed.
This parameter is used to calculate the battery State of Charge (SoC) during charge and discharge.

4.2.13 Battery min. temperature

Default value

Range

Resolution

-40°C

-40…60°C

1°C

Unit

LCD name

Modbus address

Celsius

Bat. min. T

0x1018

Threshold for the “Battery under temperature” alarm (§4.4.2.3).

4.2.14 Battery max. temperature

Default value

Range

Resolution

60°C

-40…60°C

1°C

Unit

LCD name

Modbus address

Degree Celsius

Bat. max. T

0x1019

Threshold for the “Battery over temperature” alarm (§4.4.2.4).

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4.2.15 Battery lifetime

Default value

Range

Resolution

100kh

1…100kh

1kh

Unit

LCD name

Modbus address

Kilo hours

Bat. lifetime

0x101A

Threshold for the “Battery lifetime elapsed” alarm (§4.4.2.5).

4.2.16 Ri alarm mode

Default value

Values (Modbus value)

Disabled

Disabled (0), Fixed (1), Automatic (2), Auto. Done (3)

Unit

LCD name

Modbus address

NA

Ri mode

0x101B

Mode of operation for the “Battery Ri too high” alarm (§4.4.2.2).

4.2.17 Ri nom.

Default value

Range

Resolution

1mΩ

1…300mΩ

0.1mΩ

Unit

LCD name

Modbus address

Milli ohm

Ri nominal

0x101C

Used for the threshold calculation of the “Battery Ri too high” alarm (§4.4.2.2).

4.2.18 Ri max. variation

Default value

Range

Resolution

300%

50…300%

1%

Unit

LCD name

Modbus address

Percent

Ri max. variation

0x101D

Used for the threshold calculation of the “Battery Ri too high” alarm (§4.4.2.2).

4.2.19 Operating mode

Default value

Values (Modbus value)

UPS

UPS (1), DC/DC (2)

Unit

LCD name

Modbus address

NA

Operating mode

0x1020

Defines the DCW20 operating mode. See §3.1 and §3.2 for details of each mode.

4.2.20 Nominal output voltage

Default value

Range

Resolution

10V

10…58V

0.1V

Unit

LCD name

Modbus address

Volts

Output nominal U

0x1021

UPS mode: DCW20 enters backup mode when the output voltage drops below 90% of the nominal
value, it is also the regulated output voltage during backup.
DC/DC mode: it corresponds to the regulated output voltage.

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4.2.21 Max. input current

Default value

Range

Resolution

20A

5…21A

0.1A

Unit

LCD name

Modbus address

Amperes

Max input I

0x1022

UPS mode: DCW20 limits the maximum input current to this value reducing the battery charging
current if necessary.
DC/DC mode: DCW20 limits the maximum input current (in DC/DC mode the input is connected to
the battery connection) to this value reducing the output voltage if necessary.

4.2.22 Max. output current

Default value

Range

Resolution

20A

5…21A

0.1A

Unit

LCD name

Modbus address

Amperes

Max output I

0x1023

DCW20 limits the maximum output current to this value reducing the output voltage if necessary.

4.2.23 Max. Backup time enable

Default value

Values (Modbus value)

Disabled

Disabled (0), Enabled (1)

Unit

LCD name

Modbus address

NA

Backup time enable

0x1024

If enabled the DCW20 shuts down if the backup last more than the “Max. backup time” value
(§4.2.24).

4.2.24 Max. backup time

Default value

Range

Resolution

1440min

1…1440min

1min

Unit

LCD name

Modbus address

Minutes

Back. time max

0x1025

If “Max. Backup time enable” field is enabled the DCW20 shuts down if the backup last more than the
specified amount of time.

4.2.25 Buzzer enable

Default value

Values (Modbus value)

Disabled

Disabled (0), Enabled (1)

Unit

LCD name

Modbus address

NA

Buzzer enable

0x1026

Enable/Disable buzzer sound in case of alarm.

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4.2.26 Relay 1 configuration

Default value

Flags (bit)

Normally open, Bat. life time,
Bat. Ri too high, Bat. Charge
failure

Normally open (0), Backup (1), Soc < 25% (2), Bat. life time (3),
Bat. Ri too high (4), Bat. Low (5), Bat. Disconnected (6), Bat.
charge failure (7), Backup left < 25% (8)

Unit

LCD name

Modbus address

NA

Relay 1

0x1027

This field defines the behavior of relay 1 as follows:

Normally open

1 or more enabled state active?

Relay contact status

True

No

Open

True

Yes

Closed

False

No

Closed

False

Yes

Open

4.2.27 Relay 2 configuration

Default value

Flags (bit)

Normally open, Backup

Normally open (0), Backup (1), Soc < 25% (2), Bat. life time (3),
Bat. Ri too high (4), Bat. Low (5), Bat. Disconnected (6), Bat.
charge failure (7), Backup left < 25% (8)

Unit

LCD name

Modbus address

NA

Relay 2

0x1028

This field defines the behavior of relay 2 (see “Relay 1 configuration”).

4.2.28 Inhibit polarity

Default value

Values (Modbus value)

High

Low (1), High (2)

Unit

LCD name

Modbus address

NA

Inhibit polarity

0x1029

Selects the active polarity of the inhibit input. See §3.4 for more information about the inhibit function.

4.2.29 DC/DC output mode

Default value

Values (Modbus value)

Single

Single (1), Parallel (2)

Unit

LCD name

Modbus address

NA

DC/DC out mode

0x102A

Select parallel mode in case the DCW20 is configure as DC/DC with output connected in parallel with
another unit (§3.2.1).

4.2.1 Output enable

Default value

Values (Modbus value)

Single

Single (1), Parallel (2)

Unit

LCD name

Modbus address

NA

Output enable

0x102B

Enable/Disable output.

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4.2.1 Aux enable

Default value

Values (Modbus value)

Single

Single (1), Parallel (2)

Unit

LCD name

Modbus address

NA

Aux enable

0x102C

Enable/Disable auxiliary output.

4.2.2 PC shutdown enable

Default value

Values (Modbus value)

Disabled

Disabled (0), Enabled (1)

Unit

LCD name

Modbus address

NA

PC shutdown enable

0x1030

See §3.1.5.

4.2.3 PC automatic restart enable

Default value

Values (Modbus value)

Disabled

Disabled (0), Enabled (1)

Unit

LCD name

Modbus address

NA

PC restart enable

0x1031

See §3.1.5.

4.2.4 PC shutdown delay

Default value

Range

Resolution

3600s

1…3600s

1s

Unit

LCD name

Modbus address

Seconds

PC shutdown delay

0x1032

See §3.1.5.

4.2.5 PC shutdown time

Default value

Range

Resolution

600s

1…600s

1s

Unit

LCD name

Modbus address

Seconds

PC shutdown time

0x1033

See §3.1.5.

4.2.6 PC restart minimum time

Default value

Range

Resolution

1s

1…60s

1s

Unit

LCD name

Modbus address

Seconds

PC restart time

0x1034

See §3.1.5.

4.2.7 PC off detection current threshold

Default value

Range

Resolution

0A

0…20A

0.1A

Unit

LCD name

Modbus address

Amperes

PC OFF I

0x1035

See §3.1.5.

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4.2.8 PC off detection timer

Default value

Range

Resolution

1s

1…60s

1s

Unit

LCD name

Modbus address

Seconds

PC OFF time

0x1036

See §3.1.5.

4.2.9 Battery installation date

Default value

Range

1st January 2000

from 1st January 2000 to 31st December 2099

Unit

LCD name

Modbus address

NA

Bat. installation date

0x1100

This field is used to compute the battery lifetime. If the battery lifetime exceeds the “Battery lifetime”
value (§4.2.15), the “Battery lifetime elapsed” alarm (§4.4.2.5) activates.

4.2.10 Battery charge cycles

Default value

Range

Resolution

0

0…65535

1

Unit

LCD name

Modbus address

Cycles

Bat. charge cycles

0x1104

The value increments automatically at the end of a battery charge cycle.

4.3 Info

While in the info menu, use the UP/DOWN KEY to navigate through the menu items. The fields are
also accessible via Modbus at the specified address. Modbus device identification fields are read
using function 43/13 (0x2B/0x0E) at the specified object id.

4.3.1 Firmware version

LCD name

Modbus

FW version

Device Identification Object Id 0x02

3.3 digit indicating the firmware major minor version

4.3.2 Firmware subversion

LCD name

Modbus

FW subversion

Device Identification Object Id 0x80

3 digit indicating the firmware subversion.

4.3.3 Build date

LCD name

Modbus

Build date

Device Identification Object Id 0x82

Firmware build date.

4.3.4 Build time

LCD name

Modbus

Build time

Device Identification Object Id 0x83

Firmware build time.

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4.3.5 Serial number

LCD name

Modbus

S/N

Device Identification Object Id 0x81

Device serial number.

4.3.6 Boot cycles

Unit

LCD name

Modbus address

Cycles

Boot cycles

0x2010

Counter of power ON cycles.

4.3.7 Operating time

Unit

LCD name

Modbus address

Hours

Operating time

0x2020

DCW20 operating hour counter.

4.3.8 Battery operating time

Unit

LCD name

Modbus address

Hours

Bat. operating time

0x2022

Hours elapsed since the “Battery installation date” (§4.2.9).

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4.4 Logs

Every event is logged in the device FLASH memory. From the log menu the user can view their
history. Use the UP/DOWN KEYS to navigate between logs, 2 logs are visible simultaneously on the
LCD.

1. Time: time at which the log occurred.

2. Date: date at which the log occurred.

3. Name: unique log name

4. Primary value: optional, see below for details.

5. Secondary value: optional, see below for
details.

Logs are of 3 different kinds: info, alarms and events. All info and alarms have an associated
Modbus field representing the current status (0 if inactive or 1 if active). For info and alarms a log is
generated at each status transaction. In case of active alarm, the front LED and the buzzer turn ON.

4.4.1 Info

4.4.1.1 Battery charging

LCD name

Modbus address

Bat charging

0x4000

Value1

Value2

Inactive (0), Active (1)

Not used

Active when the battery is charging.

4.4.1.2 Battery floating

LCD name

Modbus address

Bat floating

0x4001

Value1

Value2

Inactive (0), Active (1)

Not used

Active when the battery is fully charged.

4.4.1.3 Battery discharging

LCD name

Modbus address

Bat. discharging

0x4002

Value1

Value2

Inactive (0), Active (1)

Not used

Active when the battery is discharging.

4.4.1.4 USB powered

LCD name

Modbus address

USB powered

0x4020

Value1

Value2

Inactive (0), Active (1)

Not used

DCW20 is powered by USB only.

Table 6: Log screen

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4.4.1.5 Cold start

LCD name

Modbus address

Cold start

0x4021

Value1

Value2

Inactive (0), Active (1)

Not used

DCW20 has powered ON through cold start (see §3.1.6).

4.4.1.6 PC shutdown

LCD name

Modbus address

PC shutdown

0x4022

Value1

Value2

Inactive (0), Active (1)

Not used

Command to shutdowns the PC (see §3.1.5).

4.4.1.7 PC power off

LCD name

Modbus address

PC power OFF

0x4023

Value1

Value2

Inactive (0), Active (1)

Not used

Command to power OFF the PC (see §3.1.5), DCW20 output switches OFF.

4.4.1.8 External temperature sensor presence

LCD name

Modbus address

Ext. T sensor presence

0x4024

Value1

Value2

Inactive (0), Active (1)

Not used

Active if the optional external temperature sensor is connected.

4.4.1.9 Inhibit

LCD name

Modbus address

Inhibit

0x4025

Value1

Value2

Inactive (0), Active (1)

Not used

Active if the inhibit input signal is asserted (see §3.4).

4.4.1.10 Output disabled

LCD name

Modbus address

Output disabled

0x4026

Value1

Value2

Inactive (0), Active (1)

Not used

Active if the output is disabled in settings.

4.4.1.11 Auxiliary output disabled

LCD name

Modbus address

Aux disabled

0x4027

Value1

Value2

Inactive (0), Active (1)

Not used

Active if the auxiliary output is disabled in settings.

4.4.2 Alarms

4.4.2.1 Battery disconnected

LCD name

Modbus address

Bat. disconnected

0x4010

Value1

Value2

Inactive (0), Active (1)

Not used

Active when no battery is detected by DCW20.

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4.4.2.2 Battery Ri too high

LCD name

Modbus address

Bat. Ri too high

0x4011

Value1

Value2 (Milli ohm)

Inactive (0), Active (1)

Status 0 → 1: Offending threshold
Status 1 → 0: Max. measured value

Active when measured battery internal resistance exceed the alarm threshold (see §3.1.2)

4.4.2.3 Battery under temperature

LCD name

Modbus address

Bat. under temperature

0x4012

Value1

Value2 (Degree Celsius)

Inactive (0), Active (1)

Status 0 → 1: Offending threshold
Status 1 → 0: Min. measured value

Active when the battery measured temperature (using the optional external sensor) is under the
threshold specified in “Battery min. temperature” field (§4.2.13). If active the battery charged is
disabled.

4.4.2.4 Battery over temperature

LCD name

Modbus address

Bat. over temperature

0x4013

Value1

Value2 (Degree Celsius)

Inactive (0), Active (1)

Status 0 → 1: Offending threshold
Status 1 → 0: Max. measured value

Active when the battery measured temperature (using the optional external sensor) exceed the
threshold specified in “Battery max. temperature” field (§4.2.14). If active the battery charged is
disabled.

4.4.2.5 Battery lifetime elapsed

LCD name

Modbus address

Bat. lifetime elapsed

0x4014

Value1

Value2 (Hours)

Inactive (0), Active (1)

Status 0 → 1: Offending threshold
Status 1 → 0: Max. calculated value

Active when the actual calculated battery lifetime exceeds the threshold specified in “Battery lifetime”

field (§4.2.15).

4.4.2.6 Battery charge failure

LCD name

Modbus address

Bat. charge fail

0x4015

Value1

Value2

Inactive (0), Active (1)

Not used

Active when DCW20 could not charge the battery correctly. When active, the battery charger is
disabled. Disconnect the battery to reset the alarm.

4.4.2.7 Battery SoC < 25%

LCD name

Modbus address

Bat. SoC < 25%

0x4016

Value1

Value2

Inactive (0), Active (1)

Not used

Active when the battery State of Charge is under 25% of the nominal full charge capacity.

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4.4.2.8 Battery over discharge current

LCD name

Modbus address

Bat. over discharge I

0x4017

Value1

Value2 (Amperes)

Inactive (0), Active (1)

Status 0 → 1: Offending threshold
Status 1 → 0: Max. measured value

Active when the measured battery discharge current reaches the threshold specified in “Battery max.
discharge current” field (§4.2.11).

4.4.2.9 Battery low

LCD name:

Modbus address

Bat. low

0x4018

Value1

Value2 (Volts)

Inactive (0), Active (1)

Status 0 → 1: Offending threshold
Status 1 → 0: Min. measured value

Active when the measured battery voltage is under the threshold specified in “Battery low voltage”
field (§4.2.9).

4.4.2.10 Battery deep discharged

LCD name

Modbus address

Bat. deep discharge

0x4019

Value1

Value2 (Volts)

Inactive (0), Active (1)

Status 0 → 1: Offending threshold
Status 1 → 0: Min. measured value

Active when the battery measured voltage is under the threshold specified in “Battery deep discharge
voltage” field (§4.2.10).

4.4.2.11 Backup

LCD name

Modbus address

Backup

0x4030

Value1

Value2

Inactive (0), Active (1)

Not used

Active when the system is in backup (§3.1.1).

4.4.2.12 Input under voltage

LCD name

Modbus address

Input under voltage

0x4031

Value1

Value2 (Volts)

Inactive (0), Active (1)

Status 0 → 1: Offending threshold
Status 1 → 0: Min. measured value

Active when the measured input voltage is under 90% of the “Nominal output voltage” field (§4.2.20).

4.4.2.13 Input over voltage

LCD name

Modbus address

Input over voltage

0x4032

Value1

Value2 (Volts)

Inactive (0), Active (1)

Status 0 → 1: Offending threshold
Status 1 → 0: Max. measured value

Active when the measured input voltage exceeds 120% of the “Nominal output voltage” field
(§4.2.20).

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4.4.2.14 Output under voltage

LCD name

Modbus address

Output under voltage

0x4033

Value1

Value2 (Volts)

Inactive (0), Active (1)

Status 0 → 1: Offending threshold
Status 1 → 0: Min. measured value

Active when the measured output voltage is under 90% of the “Nominal output voltage” field (§4.2.20).

4.4.2.15 Output over voltage

LCD name

Modbus address

Output over voltage

0x4034

Value1

Value2 (Volts)

Inactive (0), Active (1)

Status 0 → 1: Offending threshold
Status 1 → 0: Max. measured value

Active when the measured output voltage exceeds 120% of the “Nominal output voltage” field

(§4.2.20).

4.4.2.16 Output overload

LCD name

Modbus address

Output overload

0x4035

Value1

Value2

Inactive (0), Active (1)

Not used

Active when the measured output current reaches the threshold specified in “Max. output current” field
(§4.2.22).

4.4.2.17 Input over current

LCD name

Modbus address

Input over current

0x4036

Value1

Value2

Inactive (0), Active (1)

Not used

Active when the measured input current reaches the threshold specified in “Max. input current” field
(§4.2.21).

4.4.2.18 Auxiliary output overload

LCD name

Modbus address

Aux overload

0x4037

Value1

Value2

Inactive (0), Active (1)

Not used

Active when an excessive load is detected on the auxiliary output.

4.4.2.19 External temperature sensor error

LCD name

Modbus address

Ext. T sensor error

0x4038

Value1

Value2

Inactive (0), Active (1)

Not used

Active when the external temperature sensor is not connected while it’s use is mandatory like in NiMh

battery charging.

4.4.2.20 Backup time left < 25%

LCD name

Modbus address

Backup time left < 25%

0x4039

Value1

Value2

Inactive (0), Active (1)

Not used

Active when the system is in backup and the maximal backup time is less than the “Max. backup time”
filed (§4.2.2424).

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4.4.2.21 Warning over temperature

LCD name

Modbus address

Warn. over temperature

0x403A

Value1

Value2

Inactive (0), Active (1)

Not used

Active when the internal temperature is high. If the temperature increases more the device may switch
OFF.

4.4.2.22 Error over temperature

LCD name

Modbus address

Error over temperature

0x403B

Value1

Value2

Inactive (0), Active (1)

Not used

Active when the internal temperature is too high. To prevent damage the device switches OFF.

4.4.3 Events

4.4.3.1 Power ON event

LCD name

Modbus address

Power ON

0xE000

Value1

Value2

Power ON count

Not used

Generated at every time the DCW20 is turned ON.

4.4.3.2 Shutdown event

LCD name

Modbus address

Shutdown

0xE001

Value1

Value2

Shutdown count

Shutdown reason:
1 - Deep discharge
2 - Max. backup time elapsed
3 - Shutdown command
4 - Reset command
5 - Inhibit signal

Generated at every time the DCW20 is turned OFF.

4.5 Wizard

The wizard assists the user during the DCW20 configuration. It should be run once at commissioning.

5 Technical Specifications

See DCW20 datasheet available on www.nextys.com.

DCW20_040-02-700-005-EH-1117

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