GERMAN METERING OP-735 User manual

OP-735 Bluetooth Optical Probe
User Manual
Date:
March 2022

1
Document Code: GM-HLP-0315-2203-018-00
GERMAN METERING GmbH
OP-735 Bluetooth Optical Probe
Reuterweg 65, 60323 Frankfurt am Main, Germany
Tel: +49 (0)69 / 77062206 Fax: +49 (0)69 / 77062205
www.german-metering.com
User Manual
Index
1How to use the device ................................................................................................2
1.1 Bluetooth Optical Probe ........................................................................................ 2
1.2 Electrical Specifications ......................................................................................... 2
1.3 Mechanical Specification........................................................................................2
USB Connector ............................................................................................ 3
Battery Indicator LEDs (Charge) ...................................................................3
STATUS Indicator LED .................................................................................3
POWER Button ............................................................................................ 3
1.4 Software Specifications .........................................................................................3
Connecting to meter ....................................................................................3
Working Modes............................................................................................4
Settings ......................................................................................................4
Upgrading Firmware .................................................................................... 5
2How to pair with Android device ..................................................................................7
3How to pair with IOS device ........................................................................................7
4How to connect in Windows 10....................................................................................8
5How to connect in Linux............................................................................................ 10
6Preparing for reading meter ...................................................................................... 12

2
Document Code: GM-HLP-0315-2203-018-00
GERMAN METERING GmbH
OP-735 Bluetooth Optical Probe
Reuterweg 65, 60323 Frankfurt am Main, Germany
Tel: +49 (0)69 / 77062206 Fax: +49 (0)69 / 77062205
www.german-metering.com
User Manual
1How to use the device
1.1 Bluetooth Optical Probe
The OP-735 is a device for communication between measurement devices that comply with
IEC62056-21 (mode C, E), IEC62056-31, DLMS standards for optical port, such as electricity
meters, gas correctors…with computers, handheld devices, tablets and other Bluetooth-enabled
devices. It is also possible to communicate in transparent mode.
The Bluetooth of OP-735 supports both Classic and BLE (Bluetooth Low Energy) modes. All
process steps of the optical port, such as pairing, the connection to the meter, and the battery
charge of the device are visible from the device’s LEDs.
The battery is Lithium Polymer with a capacity of 360mAh. It provides 14 hours working time for
each charge. Charging the device through both the adapter and the PC via a USB Type C cable is
possible.
There are some configurations in OP-735 such as Bluetooth name, Optical port frame and baud
rate, mode, etc., that can be changed through Bluetooth commands. All these commands and
their descriptions are in table 1.
1.2 Electrical Specifications
•IEC 62056-21 standard for optical port
•Bluetooth version 4.1 standard, Classic and BLE modes
•Communication with measurement devices according to IEC62056-21 (Mode C, E),
IEC62056-31, DLMS standards and TRANSPARENT mode for other standards such as
MODBUS
•10m unobstructed Bluetooth connection range
•Communication speed (baud rate) from 300 to 19200 bps
•3-colored LEDs for displaying battery charge
•Pairing status, Sending and receiving data LED indicator
•Lithium Polymer 3.7V, 360mAh battery
•On/off switch
•USB Type C port for charging
1.3 Mechanical Specification
•Weight: 50 gr
•Dimension: 32x43mm
•Magnet power: more than 15 Newtons
•Body Material: ABS
•Ambient light filter

3
Document Code: GM-HLP-0315-2203-018-00
GERMAN METERING GmbH
OP-735 Bluetooth Optical Probe
Reuterweg 65, 60323 Frankfurt am Main, Germany
Tel: +49 (0)69 / 77062206 Fax: +49 (0)69 / 77062205
www.german-metering.com
User Manual
USB Connector
The USB C connector is embedded to charge the battery. The LED1-
LED3 will flash three times after connecting the USB cable and
depending on the amount of charge, the corresponding LED will start
blinking:
•Blinking LED1: charge rate 0-33%
•Blinking LED2: charge rate 34-66%
•Blinking LED3: charge rate 67-100%
•All LEDs on: complete charge
After charge is complete, all the LEDS will stop flashing and stay on.
Battery Indicator LEDs (Charge)
These LEDs represent the amount of battery charge as follows:
•Blinking LED1: Battery charge is less than 10%
•LED 1 ON: Battery charge is 10-33%
•LED 2 ON: Battery charge is 34-66%
•LED 3 ON: Battery charge is 67-100%
STATUS Indicator LED
This LED represents the Bluetooth status. There are three colors;
Orange, Green and Red. Each color and their behavior represent
one of the following modes.
Orange: When device is turned on and also not connected to
any other device.
Green: When device is connected to another Bluetooth device.
Flashing Green: Device is communicating and transferring data
between the other Bluetooth device like tablet or notebook.
Red:At this state device is turned on but is stuck in boot state.
It indicates that device firmware is needed to be updated.
Flashing Red: Indicates optical port communication and data
transfer between device and the target device that must be read or configured.
POWER Button
The function of this button is to turn the OP-735 on and off. By pressing it, the OP-735 will turn
on and by pressing again; the OP-735 will turn off.
1.4 Software Specifications
Connecting to meter
The OP-735 is capable of connecting with all devices in IEC62056-21 standards.

4
Document Code: GM-HLP-0315-2203-018-00
GERMAN METERING GmbH
OP-735 Bluetooth Optical Probe
Reuterweg 65, 60323 Frankfurt am Main, Germany
Tel: +49 (0)69 / 77062206 Fax: +49 (0)69 / 77062205
www.german-metering.com
User Manual
Working Modes
OP-735 can work on two Transparent and IEC modes. The functionality is as follows:
IEC
In this mode the optical port is capable of changing baud rate between the IEC62056-21
standard automatically. Also, it can communicate with meters that support direct DLMS with 9600
speed(baudrate) and IEC62056-31 standard with 1200 speed automatically, no need any
additional setting
Transparent
In this case the meter does not comply with any modes in IEC described before (for example it
supports Modbus standard or the first communication frame was none of above), user shall put
optical probe in transparent mode and configure communication frame according to the optical
port setting commands. In this mode optical probe will transfer the data no matter the packet
type, to the other side.
Note. At this mode optical probe cannot do any changes in the communication frame with the
meter and will only transfer the received data from one side to another.
Settings
To send the settings or upgrade firmware, you can use any program that is capable of sending
commands using Bluetooth. You can also use windows-based application “Bluetooth Optical port
tools”.
Using Windows Application
Open “Bluetooth Optical port tools” and choose the corresponding COM port to the optical probe.
On the “Settings” section, choose the desired “commands” and click “Read” to collect data and
“Write” to configure. If the selected command has the configuration capability, the parameters
can be chosen in the “Params” section according to the configuration type.
For example, the parameters for optical port communication frame in transparent mode.
The collected value will be displayed in front of “Value” after collection.

5
Document Code: GM-HLP-0315-2203-018-00
GERMAN METERING GmbH
OP-735 Bluetooth Optical Probe
Reuterweg 65, 60323 Frankfurt am Main, Germany
Tel: +49 (0)69 / 77062206 Fax: +49 (0)69 / 77062205
www.german-metering.com
User Manual
Using Commands
The following table shows the commands associated with each configuration that must be sent to
optical probe.
Command Type
Possible options
Command
Answer
Read Serial
10 bytes digits or letters
AT+AD Serial?<CR><LF>
Serial Number=OP-
735<CR><LF>
Read Bluetooth Name
10 bytes digits or letters
AT+AD Name?<CR><LF>
Name=OP-735<CR><LF>
Set Bluetooth Name
10 bytes digits or letters
AT+AD Name=OP-
735<CR><LF>
Name=OP-735<CR><LF>
Read Optical Probe
Model
OP-735, OP-745
AT+AD Model?<CR><LF>
Model = OP-
735<CR><LF>
Read Software Version
AT+AD Software
Version?<CR><LF>
Version:01.01.01<CR>
<LF>
Read Automatic Power
Off Time (Minute)
1 to 9
AT+AD
AutoPowerOff?<CR><LF>
AutoPowerOff=5<CR><L
F>
Set Automatic Power
Off Time (Minute)
1 to 9
AT+AD
AutoPowerOff=3<CR><LF>
AutoPowerOff=3<CR><L
F>
Read Working Mode
TRANSPARENT, IEC
AT+AD Mode?<CR><LF>
CommunicationMode=IE
C<CR><LF>
Set Working Mode
TRANSPARENT, IEC
AT+AD Mode=IEC<CR><LF>
CommunicationMode=IE
C<CR><LF>
Read Optical Port Frame
Note*
AT+AD Frame?<CR><LF>
Frame=300,7,E,1<CR><
LF>
Set Optical Port Frame
Note*
AT+AD
Frame=300,7,E,1<CR><LF>
Frame=300,7,E,1<CR><
LF>
(Table no. 1)
Note*:
Set up and collection of the optical port communication frame is as follows:
•Baud rate, Number of Bit, Parity, Stop bit
The values for each parameter are as follows:
•Baud rate: 300, 1200, 2400, 4800, 9600, 19200
•Number of Bit: 7, 8
•Parity: N (none), E (even), O (odd)
According to the above description, if we want to connect with the meter with baud rate: 4800
and number of bits: eight and parity: E with the last 1 bit, the command format will be as
follows:
➢AT+AD Frame =4800,8,N,1<CR><LF>
Note*:
Generally, for meters that comply with IEC 62056-21 standard, the command should be:
➢AT+AD Frame =300,7,E,1<CR><LF>
Note*:
In case any command other than the mentioned commands are sent to the optical probe,
“Invalid Command!” will be returned and if parameters are not set correct, “Invalid Parameters!”
will be returned.
Upgrading Firmware
The firmware can be upgraded in two ways:
•Send the file through the windows-based application
•Send the file through any program via Bluetooth that can send commands

6
Document Code: GM-HLP-0315-2203-018-00
GERMAN METERING GmbH
OP-735 Bluetooth Optical Probe
Reuterweg 65, 60323 Frankfurt am Main, Germany
Tel: +49 (0)69 / 77062206 Fax: +49 (0)69 / 77062205
www.german-metering.com
User Manual
1.4.4.1Upgrade using windows-based application
In order to upgrade OP735 using “Bluetooth Optical port tools”, first choose the associated file in
“File” section by clicking on the “Select Boot File” and then press the “load boot file” button.
1.4.4.2 Upgrading via other applications
To send the file through other programs, each line of the file must be sent separately to the
device, and for each line, an ACK (06H) must be received from the device, then the next line
must be sent. If a NACK byte (15H) is received instead of ACK, that line must be resent. In fact,
receiving NACK indicates an error in the sent line format.
Sample sent file:
Send From PC: AT+AD BOOT
Receive From PC: 06
Send From PC: :020000040800F2
Receive From PC: 06
Send From PC: :10480000000E00208D4900086DB700089DB4000817
Receive From PC: 06
Send From PC: :104810000000000000000000000000000000000098
Receive From PC: 06
Send From PC: :1048200000000000000000000000000039B800088F
……

7
Document Code: GM-HLP-0315-2203-018-00
GERMAN METERING GmbH
OP-735 Bluetooth Optical Probe
Reuterweg 65, 60323 Frankfurt am Main, Germany
Tel: +49 (0)69 / 77062206 Fax: +49 (0)69 / 77062205
www.german-metering.com
User Manual
2How to pair with Android device
First, turn on the Bluetooth of android device, then turn on the OP-735, enter the Bluetooth
settings of the android device, and pair the OP-735 with it.
After pairing, there is no need to re-pair (even after turning device on and off).
These pictures show all steps of pairing OP-735 with android:
3How to pair with IOS device
Turn on the OP-735 and follow steps below:
Step 1: On your IOS device, go to Settings > Bluetooth and turn on Bluetooth. Stay on this
screen until you see the OP-735.
Step 2: Tap on OP-735.
Step 3: You might need to enter the PIN. The OP-735 pin code is “0” (zero).
After pairing, there is no need to re-pair (even after turning device on and off).

8
Document Code: GM-HLP-0315-2203-018-00
GERMAN METERING GmbH
OP-735 Bluetooth Optical Probe
Reuterweg 65, 60323 Frankfurt am Main, Germany
Tel: +49 (0)69 / 77062206 Fax: +49 (0)69 / 77062205
www.german-metering.com
User Manual
4How to connect in Windows 10
The OP-735 is Bluetooth-enabled, and other device should be Bluetooth-enabled too. To connect
OP-735 to your Computer/Laptop follow steps below:
Step 1: Make sure your device bluetooth is on and click on “Add Bluetooth or other device” in
the Bluetooth settings in Settings Menu:
Step 2: In New form click on “Bluetooth”:
Step 3: Click on found OP-735 with audio type and click “Connect”:

9
Document Code: GM-HLP-0315-2203-018-00
GERMAN METERING GmbH
OP-735 Bluetooth Optical Probe
Reuterweg 65, 60323 Frankfurt am Main, Germany
Tel: +49 (0)69 / 77062206 Fax: +49 (0)69 / 77062205
www.german-metering.com
User Manual
Step 4: Click “done” after connection is complete.
Step 5: After connecting, a COM port for the OP-735 is created on the computer, to know its
port number, scroll down to the end of the form and click on “More Bluetooth options”:
Click on “COM Ports”tab and find your OP-735 serial number with outgoing direction.

10
Document Code: GM-HLP-0315-2203-018-00
GERMAN METERING GmbH
OP-735 Bluetooth Optical Probe
Reuterweg 65, 60323 Frankfurt am Main, Germany
Tel: +49 (0)69 / 77062206 Fax: +49 (0)69 / 77062205
www.german-metering.com
User Manual
5How to connect in Linux
To connect OP-735 with your Linux device flow steps below:
Step 1: Install BlueZ packages by using any of the following commands that matches your Linux
distribution:
-----Ubuntu / Debian -----
$sudo apt-get -y install bluetooth bluez bluez-tools rfkill
-----Fedora -----
$sudo dnf -y install bluez bluez-tools
-----Arch Linux / Manjaro -----
$sudo pacman -S bluez bluez-utils
This installation provides the bluetoothctl utility.
Step 2: You need to add your account to the lp group if you wish to connect to a bluetooth
tether:
sudo usermod -aG lp $USER
newgrp lp
Step 3: Start and enable the Bluetooth:
$systemctl is-enabled bluetooth.service
enabled
Use this command to check it out:
$systemctl status bluetooth.service
Step 4: Ensure Bluetooth is not disabled:
$rfkill
ID TYPE DEVICE SOFT HARD
0 bluetooth tpacpi_bluetooth_sw blocked unblocked
1 wlan phy0 unblocked unblocked
If it is blocked, unblock it by using the command below:
$rfkill unblock bluetooth
Confirm it is unblocked:
$rfkill
ID TYPE DEVICE SOFT HARD
0 bluetooth tpacpi_bluetooth_sw unblocked unblocked
1 wlan phy0 unblocked unblocked
2 bluetooth hci0 unblocked unblocked
Step 5: Use bluetoothctl to connect to OP-735. Start the bluetoothctl interactive command:
$bluetoothctl
Agent registered
Use this command to check it out:
$bluetoothctl show

11
Document Code: GM-HLP-0315-2203-018-00
GERMAN METERING GmbH
OP-735 Bluetooth Optical Probe
Reuterweg 65, 60323 Frankfurt am Main, Germany
Tel: +49 (0)69 / 77062206 Fax: +49 (0)69 / 77062205
www.german-metering.com
User Manual
Step 6: Turn on your bluetooth adapter:
[bluetooth]# agent KeyboardOnly
Agent is already registered
[bluetooth]# default-agent
Default agent request successful
[bluetooth]# power on
Changing power on succeeded
Step 7: Turn OP-735 on and do a scan to detect it:
# scan on
Discovery started
[CHG] Controller 20:79:18:5E:4B:64 Discovering: yes
[NEW] Device 5C:FB:7C:A4:17:C6 OP-735
To stop scanning use this command:
# scan off
Step 8: To pair with OP-735 use command “ pair <Bluetooth address> ”. You may need to
confirm it.
[bluetooth]# pair 5C:FB:7C:A4:13:C6
Attempting to pair with 5C:FB:7C:A4:17:C6
[CHG] Device 5C:FB:7C:A4:13:C6 Connected: yes
Pairing successful
# trust 5C:FB:7C:A4:17:C6
[CHG] Device 5C:FB:7C:A4:17:C6 Trusted: yes
Changing 5C:FB:7C:A4:17:C6 trust succeeded
Use this command to check it out:
# paired-devices
Device 5C:FB:7C:A4:17:C6 OP-735
# devices
Device 5C:FB:7C:A4:17:C6 OP-735
Step 9: Connect to OP-735 after pairing:
[bluetooth]# connect 5C:FB:7C:A4:17:C6
Attempting to connect to 5C:FB:7C:A4:17:C6
[CHG] Device 5C:FB:7C:A4:17:C6 Connected: yes
Connection successful
Use this command to check it out:
[OP-735]# info
Device 5C:FB:7C:A4:17:C6 (public)
Name: OP-735
Alias: OP-735

12
Document Code: GM-HLP-0315-2203-018-00
GERMAN METERING GmbH
OP-735 Bluetooth Optical Probe
Reuterweg 65, 60323 Frankfurt am Main, Germany
Tel: +49 (0)69 / 77062206 Fax: +49 (0)69 / 77062205
www.german-metering.com
User Manual
6Preparing for reading meter
Turn on OP-735 and put it on the optical port of the meter. After OP is turned on and before
connecting with other Bluetooth device, LED will turn orange. First pair your tablet or laptop with
the optical probe. After pairing with tablet or laptop, the LED on OP will turn green.
If you are using pc for connecting with OP, first choose the Com port corresponding to the optical
port in the software used correctly and then start transferring data.
If you are using the meter reading application from German Metering, after pairing with tablet or
phone, in Digital collection window, choose the serial number of the optical probe and then
collect data from meter.