Siemens SENTRON PAC3200T User manual

PAC3200T

SENTRON
7KM Power Monitoring Device
PAC3200T
Equipment Manual
02/2020
L1V30415168B
-02
Introduction
1
Description
2
Mounting
3
Connection
4
Operation
5
Commissioning
6
Service and maintenance
7
Technical data
8
Dimensional drawings
9
Appendix
A

Siemens AG
Smart Infrastructure
Low Voltage Products
Postfach 10 09 53
93009 REGENSBURG
GERMANY
Ⓟ
02/2020 Subject to change
Copyright © Siemens AG 2017.
All rights reserved
Legal information
Warning notice system
This manual contains notices you have to observe in order to ensure your personal safety, as well as to prevent
damage to property. The notices referring to your personal safety are highlighted in the manual by a safety alert
symbol, notices referring only to property damage have no safety alert symbol. These notices shown below are
graded according to the degree of danger.
DANGER
indicates that death or severe personal injury will result if proper precautions are not taken.
WARNING
indicates that death or severe personal injury may result if proper precautions are not taken.
CAUTION
indicates that minor personal injury can result if proper precautions are not taken.
NOTICE
indicates that property damage can result if proper precautions are not taken.
If more than one degree of danger is present, the warning notice representing the highest degree of danger will
be used. A notice warning of injury to persons with a safety alert symbol may also include a warning relating to
property damage.
Qualified Personnel
The product/system described in this documentation may be operated only by personnel qualified for the specific
task in accordance with the relevant documentation, in particular its warning notices and safety instructions.
Qualified personnel are those who, based on their training and experience, are capable of identifying risks and
avoiding potential hazards when working with these products/systems.
Proper use of Siemens products
Note the following:
WARNING
Siemens products may only be used for the applications described in the catalog and in the relevant technical
documentation. If products and components from other manufacturers are used, these must be recommended
or approved by Siemens. Proper transport, storage, installation, assembly, commissioning, operation and
maintenance are required to ensure that the products operate safely and without any problems. The permissible
ambient conditions must be complied with. The information in the relevant documentation must be observed.
Trademarks
All names identified by ® are registered trademarks of Siemens AG. The remaining trademarks in this publication
may be trademarks whose use by third parties for their own purposes could violate the rights of the owner.
Disclaimer of Liability
We have reviewed the contents of this publication to ensure consistency with the hardware and software
described. Since variance cannot be precluded entirely, we cannot guarantee full consistency. However, the
information in this publication is reviewed regularly and any necessary corrections are included in subsequent
editions.

PAC3200T
Equipment Manual, 02/2020, L1V30415168B-02 3
Table of contents
1 Introduction................................................................................................................................................ 5
1.1 Components of the product ......................................................................................................5
1.2 Latest information .....................................................................................................................5
1.3 Security information ..................................................................................................................7
1.4 Open Source Software .............................................................................................................7
1.5 Advanced training courses .......................................................................................................8
2 Description................................................................................................................................................. 9
2.1 Features....................................................................................................................................9
2.2 Measuring inputs.....................................................................................................................11
2.3 Averaging measured values ...................................................................................................14
2.4 Power demands and counters ................................................................................................15
2.4.1 Acquisition of power demand..................................................................................................15
2.4.2 Energy counters......................................................................................................................16
2.5 History of active energy consumption.....................................................................................17
2.6 Digital inputs and outputs .......................................................................................................17
2.6.1 Digital Input .............................................................................................................................17
2.6.2 Digital output ...........................................................................................................................18
2.7 Communication .......................................................................................................................20
3 Mounting.................................................................................................................................................. 21
3.1 Introduction .............................................................................................................................21
3.2 Installation steps .....................................................................................................................22
3.3 Removal..................................................................................................................................22
4 Connection .............................................................................................................................................. 23
4.1 Safety notes ............................................................................................................................23
4.2 Connections ............................................................................................................................26
4.3 Connection examples .............................................................................................................27
4.4 Connecting the Ethernet communication cable ......................................................................34
4.4.1 Grounding for Ethernet ...........................................................................................................34
5 Operation................................................................................................................................................. 37
5.1 Device interface ......................................................................................................................37
5.1.1 Displays and operator controls ...............................................................................................37
5.1.2 SW button ...............................................................................................................................38

Table of contents
PAC3200T
4Equipment Manual, 02/2020, L1V30415168B-02
5.2 Supporting software ............................................................................................................... 38
5.2.1 powermanager ....................................................................................................................... 38
5.2.2 powerconfig............................................................................................................................ 39
5.2.3 Web server............................................................................................................................. 39
6 Commissioning ........................................................................................................................................ 41
6.1 Overview ................................................................................................................................ 41
6.2 Applying the supply voltage ................................................................................................... 42
6.3 Parameterizing the device ..................................................................................................... 42
6.3.1 Setting basic parameters with powerconfig ........................................................................... 43
6.3.1.1 Establish connection to the device (via Ethernet).................................................................. 43
6.3.1.2 Communication parameters................................................................................................... 44
6.3.1.3 Transferring the parameters to the device............................................................................. 44
6.3.1.4 Setting basic parameters ....................................................................................................... 45
6.3.1.5 Extended (further parameters)............................................................................................... 46
7 Service and maintenance ........................................................................................................................ 57
7.1 Cleaning ................................................................................................................................. 57
7.2 Calibration .............................................................................................................................. 57
7.3 Firmware updates .................................................................................................................. 57
7.4 Troubleshooting guide ........................................................................................................... 58
7.5 Warranty................................................................................................................................. 59
8 Technical data ......................................................................................................................................... 61
8.1 Technical data........................................................................................................................ 61
8.2 Labeling.................................................................................................................................. 68
9 Dimensional drawings.............................................................................................................................. 69
A Appendix.................................................................................................................................................. 71
A.1 Modbus TCP .......................................................................................................................... 71
A.1.1 Function codes....................................................................................................................... 71
A.1.2 Modubs exception codes ....................................................................................................... 72
A.1.3 Modbus measured variables with the function codes 0x03 and 0x04 ................................... 73
A.1.4 Modbus measured variables with function code 0x14........................................................... 78
A.1.5 Structure - Digital input status and digital output status with the function codes 0x03
and 0x04 ................................................................................................................................ 84
A.1.6 Structure - Device diagnostics and device status with the function codes 0x03 and
0x04 ....................................................................................................................................... 85
A.1.7 Modbus status parameters with the function code 0x02 ....................................................... 86
A.1.8 Modbus settings with the function codes 0x03, 0x04 and 0x10 ............................................ 87
A.1.9 Modbus communication parameters with the function codes 0x03, 0x04 and 0x10 ............. 92
A.1.10 Modbus device information with the function codes 0x03, 0x04 and 0x10............................ 93
A.1.11 Modbus command parameters .............................................................................................. 94
A.1.12 Modbus standard device identification with the function code 0x02...................................... 95
A.1.13 Active energy history with Modbus function code 0x14......................................................... 96
Index...................................................................................................................................................... 105

PAC3200T
Equipment Manual, 02/2020, L1V30415168B-02 5
Introduction
1
1.1 Components of the product
The package includes:
●PAC3200T
●PAC3200T operating instructions
Available accessories
●powerconfig software
(https://support.industry.siemens.com/cs/document/63452759/update-version-
powerconfig-v3-5?dti=0&lc=en-WW)
●powermanager software (https://support.industry.siemens.com/cs/de/en/view/64850998)
1.2 Latest information
Up-to-the-minute information
You can find further support on the Internet
(https://support.industry.siemens.com/my/ww/en/requests).

Introduction
1.2 Latest information
PAC3200T
6Equipment Manual, 02/2020, L1V30415168B-02
General safety notes
DANGER
Hazardous voltage.
Will cause death, serious personal injury, or equipment damage.
Turn off and lock out all power supplying this equipment before working on this device.
WARNING
Impairment of protection will result from improper use.
Can cause death, serious personal injury, or equipment damage.
The device may be used only for the applications described in the catalog and the
associated technical documentation.
Note
These operating instructions do not purport to cover all details or variations in equipment, or
to provide for every
possible contingency in connection with installation, operation, or
maintenance. Should additional information be desired, or should particular problems arise
that are not discussed in enough detail in the operating instructions, please contact
Technical S
upport (https://www.siemens.com/lowvoltage/technical-support) for the
information you require.
Safety-related symbols on the device
Symbol
Meaning
(1) Danger of electric shock
(2) General Warning Symbol
(3) Electrical installation and maintenance by qualified personnel only

Introduction
1.3 Security information
PAC3200T
Equipment Manual, 02/2020, L1V30415168B-02 7
1.3 Security information
Siemens provides products and solutions with industrial security functions that support the
secure operation of plants, systems, machines and networks.
In order to protect plants, systems, machines and networks against cyber threats, it is
necessary to implement – and continuously maintain – a holistic, state-of-the-art industrial
security concept. Siemens’ products and solutions constitute one element of such a concept.
Customers are responsible for preventing unauthorized access to their plants, systems,
machines and networks. Such systems, machines and components should only be
connected to an enterprise network or the Internet if and to the extent such a connection is
necessary and only when appropriate security measures (e.g. firewalls and/or network
segmentation) are in place.
For additional information on industrial security measures that may be implemented, please
visit (https://www.siemens.com/industrialsecurity).
Siemens’ products and solutions undergo continuous development to make them more
secure. Siemens strongly recommends that product updates are applied as soon as they are
available and that the latest product versions are used. Use of product versions that are no
longer supported, and failure to apply the latest updates may increase customer's exposure
to cyber threats.
To keep up to date with all the latest product updates, subscribe to the Siemens Industrial
Security RSS Feed at (https://www.siemens.com/industrialsecurity).
1.4 Open Source Software
This product, solution or service ("Product") contains third-party software components.
These components are Open Source Software licensed under a license approved by the
Open Source Initiative (www.opensource.org (http://www.opensource.org)) or similar
licenses as determined by SIEMENS ("OSS") and/or commercial or freeware software
components. With respect to the OSS components, the applicable OSS license conditions
prevail over any other terms and conditions covering the Product. The OSS portions of this
Product are provided royalty-free and can be used at no charge.
If SIEMENS has combined or linked certain components of the Product with/to OSS
components licensed under the GNU LGPL version 2 or later as per the definition of the
applicable license, and if use of the corresponding object file is not unrestricted ("LGPL
Licensed Module", whereas the LGPL Licensed Module and the components that the LGPL
Licensed Module is combined with or linked to is the "Combined Product"), the following
additional rights apply, if the relevant LGPL license criteria are met: (i) you are entitled to
modify the Combined Product for your own use, including but not limited to the right to
modify the Combined Product to relink modified versions of the LGPL Licensed Module, and
(ii) you may reverse-engineer the Combined Product, but only to debug your modifications.
The modification right does not include the right to distribute such modifications and you
shall maintain in confidence any information resulting from such reverse-engineering of a
Combined Product.

Introduction
1.5 Advanced training courses
PAC3200T
8Equipment Manual, 02/2020, L1V30415168B-02
Certain OSS licenses require SIEMENS to make source code available, for example, the
GNU General Public License, the GNU Lesser General Public License and the Mozilla Public
License. If such licenses are applicable and this Product is not shipped with the required
source code, a copy of this source code can be obtained by anyone in receipt of this
information during the period required by the applicable OSS licenses by contacting the
following address:
Siemens AG
Smart Infrastructure
Low Voltage Products
Technical Support
Postfach 10 09 53
93009 Regensburg
Germany
www.siemens.com/lowvoltage/support-request
(https://support.industry.siemens.com/cs/us/en/ps)
Keyword: Open Source Request (please specify Product name and version, if applicable)
SIEMENS may charge a handling fee of up to 5 EUR to fulfil the request.
Warranty regarding further use of the Open Source Software
SIEMENS' warranty obligations are set forth in your agreement with SIEMENS. SIEMENS
does not provide any warranty or technical support for this Product or any OSS components
contained in it if they are modified or used in any manner not specified by SIEMENS. The
license conditions may contain disclaimers that apply between you and the respective
licensor. For the avoidance of doubt, SIEMENS does not make any warranty commitment on
behalf of or binding upon any third-party licensor. The Open Source Software used in the
product and the license agreements concerning this software can be found in the
Readme_OSS.
1.5 Advanced training courses
Find out about training courses on offer on the following link.
Training for Industry (https://www.siemens.com/sitrain-lowvoltage)
This is where you can choose from
●Web-based training courses (online, informative, free)
●Classroom training courses (course attendance, comprehensive, subject to fee).
You also have the possibility of compiling your own training portfolio via Learning paths.

PAC3200T
Equipment Manual, 02/2020, L1V30415168B-02 9
Description
2
2.1 Features
The PAC3200T is a measuring device for measuring the basic electrical variables in low-
voltage power distribution. The device is capable of single-phase, two-phase, or three-phase
measurement and can be used in three- or four-wire TN, TT and IT networks.
The PAC3200T is mounted on a DIN rail.
Thanks to its large measuring voltage range, the PAC3200T measuring device can be
connected directly in any low-voltage system up to a rated voltage UL-L 480 V. X / 1 A and
x / 5 A current transformers can be used for current measuring. The integrated Ethernet
interface can be used for communication.
Measurement
●Measurement of all relevant electrical variables in an AC system
●Acquisition of the minimum and maximum values of all measured variables
●Averaging of all measured values directly on the device in two steps, which are
independent of each other and freely configurable (aggregation)
Counters and average power demand values
●A number of energy counters record active, reactive and apparent energy.
●Calculation and storage of the average demand in the last measuring period for active
power and reactive power for simple generation of load profiles using software
(programmable measurement period of between 1 and 60 min.).
Display and operator control
●LED for Ethernet communication, active energy pulse indicator, Power ON/OFF and
overvoltage.
●powerconfig from Version 3.7
●powermanager
●Web server (HTTP)
Memory
●Device parameter settings are permanently stored in the device memory.
●Extreme values (maximum or minimum) are permanently stored in the internal device
memory. Values can be reset via powerconfig or Modbus command.

Description
2.1 Features
PAC3200T
10 Equipment Manual, 02/2020, L1V30415168B-02
Behavior in the case of power failure and power restore
After a power failure, the device starts back at zero with the calculation of the power demand
of the total active power and total reactive power.
Counter statuses and maximum/minimum values are written from the volatile to the non-
volatile memory at the following intervals:
Counter values:
Every 5 mins.
Maxi-
mum/minimum
values:
Every 5 secs., if available
Interfaces
●Ethernet interface
●Digital Input
●Digital output
A description of the inputs and outputs can be found in section "Digital inputs and outputs
(Page 17)".
Security
●Hardware write protection
●Access protection IP filter
●Modbus TCP port, configurable
●HTTP port, configurable
●Dynamic host configuration protocol (DHCP) included
●Simple network time protocol (SNTP) included
●Attachment of lead seals possible
A description of how to protect the device can be found in section "Extended (further
parameters) (Page 46)".
Note
Activate hardware write protection
When connecting the measuring device to a network, it is recommended that the hardware
write protection is activated.

Description
2.2 Measuring inputs
PAC3200T
Equipment Manual, 02/2020, L1V30415168B-02 11
Tariffs
PAC3200T supports 2 tariffs for the integrated energy counters (high tariff and low tariff).
Control of tariff switching
Switching between off-peak and on-peak can be controlled via the digital input or the
communication interfaces.
Time-related switching is only possible using a higher-level system.
Tariff switching after synchronization
When synchronizing the average power demand values via the communication interfaces or
the digital input, the tariff change will only become effective after expiry of the period. Without
synchronization, the tariff change takes effect immediately.
The synchronization frame contains the length of the demand period in minutes. The
synchronization command is ignored if the period length sent to the device with the
synchronization frame is different to the length parameterized in the device.
2.2 Measuring inputs
Current measurement
NOTICE
AC current measurement only.
The device is not suitable for measuring DC current.
PAC3200T is designed for:
●Measuring current of 5 A for connecting standard current transformers. Each current
measuring input can take a continuous load of 10 A. A momentary overcurrent of up to
100 A and a duration of 1 s is possible.
The powerconfig configuration software enables the current direction to be changed
individually for each phase. It is not necessary to change the terminal connections of the
current transformers in the event of connection errors.

Description
2.2 Measuring inputs
PAC3200T
12 Equipment Manual, 02/2020, L1V30415168B-02
Voltage measurement
NOTICE
AC voltage measurement only.
The device is not suitable for measuring DC voltage.
PAC3200T is designed for:
●Direct measurement on the system or using voltage transformers. External voltage
transformers are required to measure higher voltages than the permissible rated input
voltages.
●Measurement voltage up to 277 V / 480 V. The device is designed for measuring input
voltages up to 277 V to the neutral conductor and for measuring input voltages up to
480 V to the external conductor.
Connection types
Five connection types have been provided. The device can measure in single-phase, two-
phase, or three-phase mode and can be used in three- or four-wire TN, TT and IT networks.
Table 2- 1 Available connection types
Short code
Connection type
3P4W (factory setting)
3 phases, 4 conductors, unbalanced load
3P3W
3 phases, 3 conductors, unbalanced load
3P4WB
3 phases, 4 conductors, balanced load
3P3WB
3 phases, 3 conductors, balanced load
1P2W
1 phase, 2 conductors, unbalanced load
The input circuit of the device must correspond to one of the connection types listed. Select
the suitable connection type for the purpose.
You can find connection examples in the chapter Connection (Page 23).
NOTICE
The wrong system connection can damage the device.
Before connecting the PAC3200T, ensure that the local power supply conditions match the
specifications on the type plate.
The short code of the connection type must be entered in the device settings at startup. You
can find the instructions for parameterizing the connection type in the chapter
Commissioning (Page 41).

Description
2.2 Measuring inputs
PAC3200T
Equipment Manual, 02/2020, L1V30415168B-02 13
Displaying the measured variables depending on the connection type
The table below shows which measured values can be read out, depending on the
connection type.
Table 2- 2 Measured variables depending on the connection type
Connection type
Measured variable
3P4W
3P3W
3P4WB
3P3WB
1P2W
Voltage L1-N
✓
—
✓
—
✓
Voltage L
2-N
✓
—
—
—
—
Voltage L3-N
✓
—
—
—
—
Average voltage L1-N, L2-N, L3-N ✓— — — —
Voltage L
1-2
✓
✓
—
✓
—
Voltage L2-3
✓
✓
—
✓
—
Voltage L
3-1
✓
✓
—
✓
—
Average Voltage L1-2, L2-3, L3-1
✓
✓
—
✓
—
Current L
1
✓
✓
✓
✓
✓
Current L2
✓
✓
—
—
—
Current L
3
✓
✓
—
—
—
Average current L1, L2, L3
✓
✓
—
—
—
Apparent power L
1
✓
—
✓
—
✓
Apparent power L2
✓
—
—
—
—
Apparent power L
3
✓
—
—
—
—
Active power L1
✓
—
✓
—
✓
Active power L
2
✓
—
—
—
—
Active power L3
✓
—
—
—
—
Reactive power L
1
✓
—
✓
—
✓
Reactive power L2
✓
—
—
—
—
Reactive power L
3
✓
—
—
—
—
Total apparent power
✓
✓
✓
✓
✓
Total active power
✓
✓
✓
✓
✓
Total reactive power
✓
✓
✓
✓
✓
Power factor L
1
✓
—
✓
—
✓
Power factor L
2
✓
—
—
—
—
Power factor L3
✓
—
—
—
—
Total power factor
✓
✓
✓
✓
✓
Frequency
✓
✓
✓
✓
✓
THD voltage L
1
✓
—
✓
—
✓
THD voltage L2
✓
—
—
—
—
THD voltage L
3
✓
—
—
—
—
THD current L1
✓
✓
✓
✓
✓
THD current L
2
✓
✓
—
—
—
THD current L3
✓
✓
—
—
—
Active Energy Import
✓
✓
✓
✓
✓

Description
2.3 Averaging measured values
PAC3200T
14 Equipment Manual, 02/2020, L1V30415168B-02
Connection type
Measured variable
3P4W
3P3W
3P4WB
3P3WB
1P2W
Active Energy Export
✓
✓
✓
✓
✓
Reactive Energy Positive
✓
✓
✓
✓
✓
Reactive Energy Negative
✓
✓
✓
✓
✓
Apparent Energy ✓✓✓✓✓
Voltage unbalance
✓
✓
—
—
—
Current unbalance ✓✓— — —
Universal counter
✓
✓
✓
✓
✓
Operating hours counter
✓
✓
✓
✓
✓
2.3 Averaging measured values
With appropriate load profiles, consumers can carry out a targeted optimization of their
energy consumption.
Instantaneous values are averaged over specific time periods to create load profiles. For this
purpose, measured values are read out via the communication and stored. That increases
the bus load considerably and occupies storage capacity.
The PAC3200T device has two average value generators, which can be parameterized
independently. The aggregation of the measured values reduces the bus load without risk of
losing information. Average values are calculated contiguously, based on the underlying
values. The values are updated each time after expiry of the set time period.
●The default setting for average value 1 is a period of 10 seconds.
●The default setting for average value 2 is a period of 15 minutes.
The period length can be set to anything between 3 seconds and 31536000 seconds (1
year).
The list of available measured values can be found in the appendix "Modbus variables with
function code 0x14".

Description
2.4 Power demands and counters
PAC3200T
Equipment Manual, 02/2020, L1V30415168B-02 15
2.4 Power demands and counters
2.4.1 Acquisition of power demand
Values that can be read out
PAC3200T supplies the power demand of the last completed measuring period:
●Mean values for active power and reactive power, separated in each case for import and
export
●Minimum and maximum active power and reactive power
●Length of the demand period in seconds. The period may be shorter for reasons of
external synchronization.
●Time in seconds since the last synchronization or since completion of the last period.
Example: Period length and length of the demand period
Period length: 15 minutes; time of day: 13:03; time in seconds: 180 s.
The following can be calculated from this: The last demand period ended at 13:00. The
active demand period will end at 13:15 or in 12 minutes.
Availability
Note
The power demand of the last measuring period can only be recalled during the current
measuring period.
Adjustable parameters
●Time interval in minutes: 1 to 60 min adjustable, default 15 min

Description
2.4 Power demands and counters
PAC3200T
16 Equipment Manual, 02/2020, L1V30415168B-02
2.4.2 Energy counters
Energy counter
Available energy counters of the PAC3200T measuring device:
Tariff 1
Tariff 2
Total
(T1 + T2)
Active energy
kWh
Import
Total
X
X
X
L1
X
X
-
L2
X
X
-
L3 X X -
Secondary value
-
-
X
Export
Total
X
X
X
L1
X
X
-
L2
X
X
-
L3
X
X
-
Secondary value
-
-
X
Reactive energy
kvarh
Import
Total
X
X
X
L1
X
X
-
L2
X
X
-
L3
X
X
-
Export
Total
X
X
X
L1
X
X
-
L2
X
X
-
L3
X
X
-
Apparent energy
kVAh
Total
X
X
X
L1
X
X
-
L2
X
X
-
L3
X
X
-
Secondary values:
Non-resettable energy counters. Transformer ratio is not taken into account in the
calculation.

Description
2.5 History of active energy consumption
PAC3200T
Equipment Manual, 02/2020, L1V30415168B-02 17
2.5 History of active energy consumption
Based on selected recordings of energy consumption over time, users can perform a
targeted analysis of their energy consumption for the purpose of optimizing their energy
usage. The power monitoring devices have a daily energy counter and a monthly energy
counter.
●The daily energy counter records the active energy for each day of the preceding two
months.
●The monthly energy counter records the active energy for each month of the preceding
two years.
This function is available only in conjunction with communication interfaces. A list of
available measured values can be found in chapter Active energy history with Modbus
function code 0x14 (Page 96).
2.6 Digital inputs and outputs
The PAC3200T has the following inputs/outputs:
●1 digital input
●1 digital output
2.6.1 Digital Input
The following functions can be assigned to the digital input:
●Status monitoring: Capturing statuses of connected signal encoders
●Tariff switching for two-tariff counters
●Synchronization of the measuring period by means of the synchronization pulse of a
system control center or other device.
●Input for energy pulses (S0 interface)
①
External power supply, max. 30 VDC, typically 24 VDC
②
Input electronics
Figure 2-1 Block diagram: Digital inputs

Description
2.6 Digital inputs and outputs
PAC3200T
18 Equipment Manual, 02/2020, L1V30415168B-02
2.6.2 Digital output
The following functions can be assigned to the digital output:
●Not used:
The digital output is deactivated.
●Device ON:
The digital output is ON.
●Remote control:
The digital input is remotely controlled.
●Direction of rotation
The digital output is switched on by a counter-clockwise rotating electrical field and
remains active while the direction of rotation of the field remains unchanged.
●Limit violation:
The digital output is switched on by a limit violation and remains active while the limit
violation prevails.
●Energy pulse
The digital output outputs the parameterized number of pulses per energy unit (e.g. kWh).
The specified energy counter is evaluated here.
Figure 2-2 Block diagram: Digital outputs