Logic IO RTCU AX9i eco User manual

RTCU AX9i eco
Technical Manual
Version 1.01

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 2 of 30 Email: [email protected]
Denmark www.logicio.com
Introduction
This manual contains technical documentation which allows for easy installation and use of the
RTCU AX9i eco product. For information on the programming and software configuration of the
product please refer to the RTCU IDE documentation.
The RTCU AX9i eco has been designed from the ground up for professional wireless industrial
applications with its strong on-board I/O capabilities and multiple communication interfaces such
as: 1-Wire, RS232 and USB. For world-wide usage in any network environment the RTCU AX9i eco
offers a full quad-band GSM engine with a switchable dual antenna design supporting both an on-
board as well as an external GSM antenna.
The RTCU AX9i eco is based on the X32 Execution Architecture offering high performance and a
large memory capacity for both program and data - meeting the requirements of today’s most
demanding and sophisticated M2M/IoT applications.
The RTCU AX9i eco rests on the RTCU M2M Platform that brings all the necessary tools together
to develop, implement and maintain today’s sophisticated M2M/IoT applications.
The development task is supported by the free RTCU I E development environment
complimented by a large and comprehensive documentation and application example library.
The RTCU Gateway 2 is the corner-stone of the communication infrastructure ensuring reliable
two-way device communication in any network environment.
Deploying and maintaining new application and firmware versions for devices in the field are
handled by the powerful RTCU eployment Server.
For detailed information on the powerful RTCU M2M Platform, please refer to the
RTCU M2M Platform datasheet.

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 3 of 30 Email: [email protected]
Denmark www.logicio.com
The technical highlights of the RTCU AX9i eco:
 Based on the RTCU M2M Platform
1
 X32 execution architecture.
o RTCU IDE development tool with a full featured device simulator.
o Huge standard API with more than 800+ functions.
o Comprehensive protocol support, including:
TCP-UDP/IP, FTP, SMTP, RACP, MQTT.
 World-wide Quad-band GSM engine.
 Internal and external antenna connector. Selectable from application.
 Internal SIM-card reader.
 igitized audio can be played over GSM.
 TMF support for implementation of Interactive Voice Response applications.
 Large data-flash/logger memory with a capacity of 4.5 MB.
 Internal 4 MB FAT32 flash drive.
 1 x RS232 channel.
 2 x analog inputs with 0..10 volt / 0..20 mA with 12 bit precision.
 5 x digital inputs and 4 x high-power relays.
 Up to 4 digital inputs can be configured as IEC62053-31 Class A compliant.
 1-Wire bus for accessories such as ID-button reader, temperature sensors, etc.
 Wide AC/DC power operating range from 85..265VAC / 8..36 V C.
 On-board Li-Ion battery.
 Advanced power-management with wake-up on a wide range of events.
 High-speed USB programming connector.
 Housed in a ruggedized plastic encapsulation with cable glands.
 IP65 water protected for outdoor usage.
 Fully supported by the RTCU Gateway 2 and the RTCU eployment Server .
1 Please see “The RTCU M2M Platform” data sheet for more information.

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 4 of 30 Email: [email protected]
Denmark www.logicio.com
* * * * THIS PAGE IS INTENTIONALLY LEFT BLANK * * *

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 5 of 30 Email: [email protected]
Denmark www.logicio.com
Table of Contents
Introduction......................................................................................................................................................2
The technical highlights of the RTCU AX9i eco:.........................................................................................3
Graphical view.................................................................................................................................................6
Connection Overview.................................................................................................................................7
Power supply .................................................................................................................................................10
DC Supply ..................................................................................................................................................11
AC Supply..................................................................................................................................................12
Digital I/O .......................................................................................................................................................14
Relay outputs.............................................................................................................................................14
Load Noise .................................................................................................................................................14
Digital inputs / S0 inputs / wakeup (ignition) input .............................................................................15
Analog input ..................................................................................................................................................17
USB programming port ................................................................................................................................18
RS232 communication ports (EIA/TIA-232 and V.28/V.24 compatible) ................................................18
RS232 port 1 ...............................................................................................................................................18
1-Wire bus.......................................................................................................................................................19
LED Indicators ...............................................................................................................................................19
User LED A and B .....................................................................................................................................19
System LED S1 and S2 ..............................................................................................................................20
Switches ..........................................................................................................................................................21
DIP-Switch..................................................................................................................................................21
System switch (RST)..................................................................................................................................21
Internal Li-Ion battery...................................................................................................................................22
GSM .................................................................................................................................................................23
GSM Antenna ............................................................................................................................................23
SIM-Card.........................................................................................................................................................24
Barcode / unit type ........................................................................................................................................24
Power consumption ......................................................................................................................................25
External DC supply...................................................................................................................................25
Internal battery ..........................................................................................................................................25
External AC supply...................................................................................................................................26
Appendix A – Unit configuration guide ....................................................................................................27
Appendix B – Installing the SIM card.........................................................................................................29
RTCU AX9i eco Specifications.....................................................................................................................30

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 6 of 30 Email: [email protected]
Denmark www.logicio.com
Graphical view
On the front of the RTCU AX9i eco are four user controlled LED’s and three system LED’s for
simple information and status.
The external GSM antenna connector is located at the side of the device as shown below:
User Controlled
LEDs
System LED
s

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 7 of 30 Email: [email protected]
Denmark www.logicio.com
Connection Overview
Connections to external equipment are done via large and easy-to-use screw terminal blocks which
are accessible when the lid is removed. The placement of the terminals makes installation easy
using the PG glands and thereby maintaining the IP-67 protection.
The RTCU AX9i eco is delivered with three PG11 glands and additional two PG9 blind plugs that
can be replaced with PG9 glands if additional cable entry capacity should be required.
The stacked terminals contain connections for: digital inputs/outputs, analog inputs and DC power
input.
The angled terminals contain connections for the communication interfaces: RS232 Port 1 and 1-
Wire.
Also located inside the RTCU AX9i eco are the SIM card reader, DIP switches and a USB-B high-
speed programming connector.
VAC terminal
Fuse
LED’s
USB
-
B
Stacked
Terminals
Configuration
Jumpers
Angl
ed
Terminals
DIP
Switches
SIM card
reader
PG Glands
and blinds
Internal GSM
Antenna
External SMA
GSM Antenna
connector

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 8 of 30 Email: [email protected]
Denmark www.logicio.com
Stacked terminal overview
Terminal Name
TOP row BOT row
escription
R1A
R1B
Contact set for relay output 1
R2A
R2B
Contact set for relay output 2
R3A
R3B
Contact set for relay output 3
R4A
R4B
Contact set for relay output 4
N.C Not connected
PE Protective Earth terminal for AC supply.
DCIN DC power supply, positive (+) connection
XGND DC power ground, negative (-) connection
DCOUT12 Internally not connected
GND Signal ground
DI1 Digital input 1 / S0 input 1
DI2 Digital input 2 / S0 input 2
DI3 Digital input 3 / S0 input 3
DI4 Digital input 4 / S0 input 4
DI5 Digital input 5 / Wakeup (ignition) input
GND Signal ground
AI1 Analog input 1
AI2 Analog input 2
AGND Analog ground
AGND Analog ground

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 9 of 30 Email: [email protected]
Denmark www.logicio.com
Angled terminal front row overview
Terminal Name escription
SER1_TXD Transmit data from serial port 1, RS232 compatible
SER1_RXD Receive data for serial port 1, RS232 compatible
DEV_DET Reserved for accessories.
SGND Signal ground
1Wire 1-Wire bus for ID-Button / Temperature sensor
1Wire-LED 1-Wire ID-Button LED output
VAC terminal overview
Terminal Name escription
N
N
85-265VAC (50/60Hz) Null input
(internally connected)
P
P
85-265VAC (50/60Hz) Phase input
(internally connected)
USB-B connector
This is a standard USB-B connector and is used for communicating with the RTCU IDE (or other
RACP compliant application).

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 10 of 30 Email: [email protected]
Denmark www.logicio.com
Power supply
The RTCU AX9i eco unit can be supplied with either 85-265VAC (50/60Hz) or 8-36VDC or both
supply types simultaneously.
The RTCU AX9i eco also contains an internal low capacity backup battery, which will supply the
RTCU if the external power should fail or be disconnected. By default the RTCU AX9i eco is
powered down when a power fail occur. This setting however can be changed. Please consult the
RTCU-IDE on-line help for more information.
When the wakeup/ignition input is activated with a logical high, the RTCU AX9i eco unit will
wake up if it was in power down mode.
There are five different ground labels: External Ground (XGND), Signal Ground (SGND), Digital
Ground (GND), Analog Ground (AGND) and AC power ground (PE). The signal, digital and
analog grounds are filtered from the power ground. The signal, digital and analog grounds are
filtered from the power ground. External ground must only be used as DC power supply return
path. The digital ground is used as ground reference for digital I/O’s, signal ground is used as
ground reference for serial interfaces, and the analog ground is used as a low noise analog ground
reference for the analog inputs.
ual Supply Note:
The RTCU AX9i eco unit can be supplied with both VAC and VDC at the same time. The unit will
run on the VAC supply if the VDC supply voltage is < +16VDC. If the VDC supply voltage is
higher it will run on the VDC supply.
Please refer to the RTCU on-line help for information on how to check the supply type from within
an application.

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 11 of 30 Email: [email protected]
Denmark www.logicio.com
C Supply
The RTCU AX9i eco unit can be supplied with 8-36VDC from an external DC power source.
Positive power is applied to the DCIN pin and ground is connected to the XGND pin.
The DC supply of the RTCU AX9i eco is protected against wrong polarity. If a system ground are
connected to either SGND or AGND a wrong polarity on the supply lines will destroy the internal
GND connection.
Please Note:
Minimum 16VDC supply is necessary for digital inputs 1-4 to work as S0 compliant inputs.
V C Supply terminals
Terminal Name escription
DCIN Power supply, positive (+) connection
XGND Power ground, negative (-) connection

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 12 of 30 Email: [email protected]
Denmark www.logicio.com
AC Supply
The RTCU AX9i eco unit can be supplied with 85-265VAC (50/60Hz) from a standard wall plug or
any other high-voltage VAC power rail. The AC supply of the RTCU AX9i eco is a high-efficient
switch mode power supply and the AC input is protected with a 1A/250V Fast Acting fuse.
The AC must be applied between the N and P on the separate located screw terminals. A
Protective Earth (PE) connection exists on the bottom row of the stacked terminals.
VAC Supply terminals
Terminal Name escription
N
N
85-265VAC (50/60Hz) Null input
(internally connected)
P
P
85-265VAC (50/60Hz) Phase input
(internally connected)
PE Protective Earth connector
Please Note:
The two pairs of N and P terminals are internally connected.
There is high voltage on certain areas of the PCB (Printed Circuit Board) when supplied with AC
mains. There is risk of electrical hazard, avoid touching the PCB and the
components during operation.
Be aware that the supply filter contains capacitors that may remain charged
after the equipment is disconnected from the supply. Although the stored
energy is within the approved safety requirements, a slight shock may be felt if
the plug pins are touched immediately after removal.
Refer all servicing and handling to qualified personnel.
VAC terminal
1A/250V Fast
Acting fuse
Protective Earth
terminal

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 13 of 30 Email: [email protected]
Denmark www.logicio.com
Please Note:
The DC ground of the AX9 series is isolated from the AC ground because of the nature of AC-to-
DC converting. As these two grounds are not tied together anywhere in the AX9, the DC ground
may appear as "floating ground" to the outside if the AX9 ground is not connected to the same
reference as the outside, and a potential difference may occur. This difference can interrupt the
behavior of the unit, and in worst case can damage the part of the unit. This must be taken in
consideration when the AX9 series are supplied with AC supply. When the AX9 is supplied with
DC voltage this "potential difference" issue may not be observed, as the DC power supply has
usually the same potential as the rest of the system.
In order to avoid the potential difference the Earth connection on the AC supply rail can be
connected to the terminal that has been labeled “PE”.
For circuitry in situations where significant Earth ground currents can flow isolating the DC
ground from Earth grounds may be desired. In this case the DC ground may be tied together with
the Earth ground through a high impedance connection.
In other situations where a common reference needed the best EMI performance and ESD
immunity can be achieved connecting the DC ground and Earth ground with a low-inductance
connection.

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 14 of 30 Email: [email protected]
Denmark www.logicio.com
igital I/O
The RTCU AX9i eco unit has five digital inputs and four normally-open relay outputs.
The outputs are high performance relays with good current handling capabilities.
Digital input 1-4 offers several operation modes. Please refer to the digital input section for
additional information.
Relay outputs
The digital outputs control four relays and they act like a normally-open contact, where one side
must be connected to a source that needs switching and the other contact terminal is the output.
The source can be either VAC or VDC but the maximum switchable voltage and current must not
be exceeded, please refer to specification page.
There are no internal connections to the relay outputs and therefore a source must always be
connected to one of the relay terminals for the output to work. If power is removed or a power-fail
occurs on the RTCU AX9i eco will switch to normally-open.
The RTCU AX9i eco unit offers a very advanced power management, which makes it possible to
have one or more outputs enabled while the RTCU is in low power mode. Please consult the RTCU
IDE on-line help for more information.
Relay output terminals
Terminal Name escription
R1A
R1B
Contact set for relay output 1
R2A
R2B
Contact set for relay output 2
R3A
R3B
Contact set for relay output 3
R4A
R4B
Contact set for relay output 4
Load Noise
If highly inductive loads (such as high power contactors) are connected to the relays it is
recommended to externally connect a clamping diode in parallel with each inductive DC load or
connect an RC snubber circuit in parallel with each inductive AC load.
For DC applications Vishay UF5405-E3/54 or similar is recommended and for AC applications
AMPOHM FE-SP-HDR23-47/100 (47nF/100 ohm) or similar is recommended.

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 15 of 30 Email: [email protected]
Denmark www.logicio.com
igital inputs / S0 inputs / wakeup (ignition) input
The five digital inputs are all low-pass filtered (450kHz) and transient-protected. To activate the
inputs, connect a positive voltage between the corresponding input (DINx) and SGND.
Digital input 1-4 can be configured individually as S0 input (IEC62053-31, Class ) and DIN5 can
work as a wakeup (ignition) input.
As default the digital inputs are configured as normal inputs. For placement and configuration of
the hardware jumpers inside the unit, please refer to the configuration guide in Appendix A.
S0 compliant inputs (IEC62053-31, Class compatible)
In S0 configuration the relevant RTCU AX9i eco input will act as a ‘pulse input device’, and a
current is supplied into the input connector so that a simple switch between SGND and the
appropriate input will activate it. This is used in most electricity metering equipment.
Please note: The RTCU AX9i eco unit must be supplied with a minimum of 16 VDC or AC power
for the S0 mode to work correctly.
S0 is enabled by default and may be disabled by the application to save power.

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 16 of 30 Email: [email protected]
Denmark www.logicio.com
Wakeup (ignition) input
The DIN5 / wakeup (ignition) input is a special input in that it also functions as the wakeup input.
If the input is activated with a logical high or low (Wait For Event mode only) when the RTCU
AX9i eco is in low-power mode it will wake-up the unit. A power apply will also wake the unit up
if it is in power-down mode or in Wait For Event mode with power Apply and/or ignition selected
for wakeup. The input is de-bounced with a period between 1-2 ms when used as a digital input.
So any logical level applied to this input must be greater than 2 ms to be valid.
The power management allows for the possibility of configuring a wakeup on one or more digital
inputs with individually configured falling- or rising edge detection. Please consult the RTCU IDE
on-line help for more information.
igital input terminals
Terminal Name escription Jumper Setting
DI1 Digital input 1 or
S0 input 1
JPDI1 in position N (default)
JPDI1 in position S
DI2 Digital input 2 or
S0 input 2
JPDI2 in position N (default)
JPDI2 in position S
DI3 Digital input 3 or
S0 input 3
JPDI3 in position N (default)
JPDI3 in position S
DI4 Digital input 4 or
S0 input 4
JPDI4 in position N (default)
JPDI4 in position S
DI5 Digital input 5 and
Wakeup (ignition) input
GND Digital Ground
For placement and configuration of the hardware jumpers inside the unit, please refer to the unit
configuration guide in Appendix A.

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 17 of 30 Email: [email protected]
Denmark www.logicio.com
Analog input
The RTCU AX9i eco unit has two analog inputs which can be configured individually to work
either as voltage or current measurement inputs by using the configuration jumper. The range in
voltage mode is 0-10VDC and in current mode it is 0-20mA.
The conversion resolution is 12 bit.
By default the analog inputs are configured as voltage inputs, and are converted to a digital value
with a resolution of 10-bit before being presented to the application (0..1023). The application can
change the resolution to the full 12 bit (0..4095). Please consult the RTCU IDE for further details.
The input signal is connected between AINx and AGND. AGND must be connected to the
reference of the connected equipment. Please be aware that deviations may occur, as the system is
very noise sensitive. Avoid long, unshielded wires and high current, fast changing signals routed
parallel to the analog signals.
Analog input terminals
Terminal Name escription Jumper Setting
AI1 Analog input 1 – Voltage
Analog input 1 – Current
JPAI1 not installed (default)
JPAI1 installed
AI2 Analog input 2 – Voltage
Analog input 2 – Current
JPAI2 not installed (default)
JPAI2 installed
AGND Analog ground
AGND Analog ground
Specification for each analog input (voltage mode)
Min. Typ. Max. Unit
0 - 10 VDC
Resolution - - 12 Bit
Precision -1.5 - 1.5 %FSR
Cut-off frequency - 4.5 - kHz
Input impedance - 40 - kΩ
Protected against transients and
low-pass filtered
Precision is based on
measurements @ 25 ˚C
Specification for each analog input (current mode)
Min. Typ. Max. Unit
0 - 20 mA
Resolution - - 12 Bit
Precision -1.5 - 1.5 %FSR
Cut-off frequency - 4.5 - kHz
Input impedance - 504 - Ω
Protected against transients and
low-pass filtered
Precision is based on
measurements @ 25 ˚C
For placement and configuration of the hardware jumpers inside the unit, please refer to the unit
configuration guide in Appendix A.

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 18 of 30 Email: [email protected]
Denmark www.logicio.com
USB programming port
The USB port is for programming and communicating with the RTCU IDE (or other RACP
compliant application). A standard USB cable can be used between the unit and the PC.
RS232 communication ports (EIA/TIA-232 and V.28/V.24 compatible)
One general purpose RS232 ports available on the RTCU AX9i eco unit. The serial input is
compliant with the EIA/TIA-232 standard.
RS232 port 1
This port is a general-purpose RS232 serial port and does not support handshaking.
The signals are available on the angled front row terminals.
SER1 terminals
Terminal Name escription
SER1_TXD Transmit data from serial port 1, RS232 compatible
SER1_RXD Receive data for serial port 1, RS232 compatible
SGND Signal ground

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 19 of 30 Email: [email protected]
Denmark www.logicio.com
1-Wire bus
The 1-Wire bus is available on the angled front row terminals. All 1-Wire communication goes
through a single connection, and all 1-Wire devices connected to this connection retrieves its
power directly from the bus (called parasitic power). For this only two wires are needed – the 1-
wire signal and the ground reference – allowing minimal cable installations.
For 1-Wire ID-Button readers, which include a built-in LED, a dedicated output is available for this
purpose. Please consult the RTCU IDE documentation for further information.
For further information regarding modular 1-wire concept, please refer to the document “Modular
1-Wire Concept Technical Manual” on the Logic IO webpage.
1-Wire terminals
Name escription
1Wire 1-Wire bus
1Wire-LED 1-Wire ID-Button LED output
SGND Signal ground
LE Indicators
Three bi-colored (red and green) and a single yellow LED indicators are present on the front of the
unit (see graphical view section).
Two bi-colored LED’s (A and B) are available to the user and the remaining two LED’s (S1 and S2)
are indicating the status and possible errors of the RTCU unit.
User LE A and B
LED A and B are composed of four individually controllable LEDs:
• LED named A on the front consists of LED 1 (green) and LED 2 (red).
• LED named B on the front consists of LED 3 (green) and LED 4 (red).
They are easily accessed from within the application program, and it is possible to mix the LED’s
to obtain a third color: yellow. Please consult the RTCU IDE documentation for more information.

RTCU AX9i eco Technical Manual V1.01
Logic IO ApS. Ph: ([phone]
Holmboes All 14 Fax: [phone]
8700 Horsens Page 20 of 30 Email: [email protected]
Denmark www.logicio.com
System LE S1 and S2
The RTCU is equipped with two system LED’s which shows the status and possible errors of the
RTCU unit.
The different patterns are listed in the table below. If the color of the system LED S1 is yellow, the
unit is actively communicating with the RTCU IDE (or another program, supporting the RTCU
RACP protocol).
The single yellow LED is signaling either the GSM module activity, or if all other LED’s are off,
that the RTCU is in the “wait for event” low power state.
S1: System LE 1 pattern overview
Pattern Description
Fastest blinking, green The unit is initializing, preparing to start the application.
Fast blinking, green
2
The unit has been forced into recovery mode with the use of
the system switch. The application is not executing.
500ms On / 500ms Off green
2
The unit is executing the application program
1.5s On / 0.5s Off. green
2
The unit is executing the application program, while
charging the internal back-up battery.
Fast blinking, red
2
A runtime error has been detected in the program.
Use the RTCU IDE to obtain the fault log.
Alternating Fast/Slow, red
2
The unit has lost its firmware! This can only happen if,
during a firmware upgrade, the RTCU unit loses power or
the communication is lost completely. In this case, simply
upload the firmware to the unit again.
75ms On / 925ms Off, green Execution speed is different from full-speed.
S2: System LE 2 pattern overview (GSM activity and “Wait For Event”)
Pattern Operating Status
Off The GSM module is turned off
600 ms On / 600 ms Off Missing SIM card or PIN code.
Network search and logon in progress.
75 ms On / 3 s Off Logged on to the network.
75 ms On / 75 ms Off /
75 ms On / 3 s OFF
A GPRS session is active.
Flashing Indicates GPRS data transfer.
On A voice or CSD session is active.
8 s OFF / 10 ms ON
(and all other LED’s OFF)
The RTCU unit is in low-power “Wait For Event” state.
2 Or yellow when communicating with the RTCU IDE or another program, supporting the RTCU RACP protocol).