GRAS 12BA User manual

Instruction Manual
GRAS 12BA 1-Channel CCP Power Module with TEDS Support
GRAS 12BE 2-Channel CCP Power Module with TEDS Support
GRAS 12BB 4-Channel CCP Power Module with TEDS Support
GRAS 12BC 1-Channel LEMO Power Module with TEDS Support
GRAS 12BF 2-Channel LEMO Power Module with TEDS Support
GRAS 12BD 4-Channel LEMO Power Module with TEDS Support
LI0280 – 19 January 2022

12Bx Power Modules
Instruction Manual
Copyright Notice
©2021 - 2022 GRASSound & Vibration A/S
grasacoustics.com
Any technical documentation that ismadeavailable byGRAS is the
copyrighted work ofGRAS and is owned by GRAS.
The content in this document is subject to changewithout notice. GRAS
Sound & Vibration is not liable orresponsible for any errors or inaccuracies
that may appear in this document.
Trademarks
Any product names mentioned inthis document may be trademarks or
registered trademarks of their respective companies and are hereby
acknowledged.
8211.0373.001
XII01191861
January 2022
Any feedback or questions concerning this document are welcome at
[e-mail]
Revision Date Description
1 22 January 2021 First Edition
2 19 January 2022 Additional power modules added (Second Edition)

Table of Contents
1 | Introduction - - - - - - - - - - - - - - - - - - - - - - - - -3
1.1 CCP Power Modules - - - - - - - - - - - - - - - - - - - - - 3
1.2 Traditional Power Modules - - - - - - - - - - - - - - - - - 4
2 | External Features - - - - - - - - - - - - - - - - - - - - - 5
2.1 CCP Preamplifier Support - - - - - - - - - - - - - - - - - - 7
2.2 Input/Output - - - - - - - - - - - - - - - - - - - - - - - 8
3|Operation - - - - - - - - - - - - - - - - - - - - - - - - - 9
3.1 Channel Indicators and Assignment - - - - - - - - - - - - - 9
3.2 TEDS Support - - - - - - - - - - - - - - - - - - - - - - - 9
3.3 SysCheck2 Support - - - - - - - - - - - - - - - - - - - - 10
3.4 Input/Output Functions - - - - - - - - - - - - - - - - - - 10
3.5 Connection and Configuration - - - - - - - - - - - - - - - 11
4 | Accessing TEDS Data - - - - - - - - - - - - - - - - - - - 13
4.1 Setting up for TEDS Data - - - - - - - - - - - - - - - - - - 13
5 | Accessing SysCheck2 - - - - - - - - - - - - - - - - - - 21
5.1 SysCheck2 commands using the Mic Power Module App - - - 21
5.2 Using SysCheck2 with APx500 Software - - - - - - - - - - 26
A | LEMO Microphone Power Supply Specifications - - - - 27
A.1 USB Interface - - - - - - - - - - - - - - - - - - - - - - - 27
A.2 External Power - - - - - - - - - - - - - - - - - - - - - - 27
A.3 Microphone Channel - - - - - - - - - - - - - - - - - - - - 28
A.4 General/Environmental - - - - - - - - - - - - - - - - - - - 29
B | CCP Microphone Power Supply Specifications - - - - 31
B.1 USB Interface - - - - - - - - - - - - - - - - - - - - - - - 31
B.2 Microphone Channel - - - - - - - - - - - - - - - - - - - - 31
B.3 General/Environmental - - - - - - - - - - - - - - - - - - - 33
C | Safety - - - - - - - - - - - - - - - - - - - - - - - - - - - 35
C.1 Safety Information - - - - - - - - - - - - - - - - - - - - - 35
C.2 Consignes de sécurité - - - - - - - - - - - - - - - - - - - 38

C.3 Información de seguridad - - - - - - - - - - - - - - - - - 40
D | Warranty, Service and Repair - - - - - - - - - - - - - 43
D.1 Warranty - - - - - - - - - - - - - - - - - - - - - - - - - 43
D.2 Service and Repairs - - - - - - - - - - - - - - - - - - - - 43
Index - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 45

3
1 | Introduction
The GRAS 12Bx family of power modules provide traditional power
for non-polarized transducers and preamplifiers (with LEMO con-
nectors) or constant current power (CCP) polarized transducers
and preamplifiers (with BNC connectors). Modules are available
with one, two, or four channels. The configurations are:
• GRAS 12BA (1-Channel CCP Power Module)
• GRAS 12BC (1-Channel LEMO Power Module)
• GRAS 12BE (2-Channel CCP Power Module)
• GRAS 12BF (2-Channel LEMO Power Module)
• GRAS 12BB (4-Channel CCP Power Module)
• GRAS 12BD (4-Channel LEMO Power Module)
When used in conjunction with the GRAS Mic Power Module App or
an Audio Precision APx analyzer instrument (available separately)
and a connected personal computer (PC), the modules can provide
access to Transducer Electronic Data Sheet (TEDS) data on TEDS-
enabled microphones. Additionally, when a SysCheck2™ -enabled
CCP microphone is used, you can remotely verify that the micro-
phone is functioning within referenced parameters.
1.1 CCP Power Modules
The GRAS CCP Power Modules with TEDS Support (12BA, 12BB and
12BE) are SysCheck2-enabled USB-powered pass-through power
modules that provide power to microphones without signal degra-
dation, gain modification, or attenuation. Power is provided for CCP
transducers and preamplifiers (also known as ICP®transducers
and preamplifiers) through BNC connections. The 12BA supports a
single CCP microphone preamplifier, the 12BE supports up to two
and the 12BB supports up to four CCP microphone preamplifiers. If
more than four microphones are required, multiple power modules
can be used concurrently. Power is provided through the USB cable
using a USB 2.0 or USB 3.0 port on the PC and a USB-C port on the
power module.

4 | 12Bx Power Modules Instruction Manual
Examples of GRAS products requiring a CCP supply are:
•246AE½″Free-field SysCheck2 Microphone Set.
•46BD½″CCP Pressure Microphone Set.
•46AE½″Free-field Microphone Set.
•40PHArrayMicrophones.
1.2 Traditional Power Modules
The GRAS LEMO Power Modules (12BC, 12BD and 12BF) are DC-
powered pass-through power modules that provide power to
microphones without signal degradation, gain modification, or
attenuation. Power is provided through the USB C port when con-
nected to a port that can supply the minimum 1.5 A required by the
module. AC mains power can also be supplied through the AUX
PWR port if the minimum 1.5 A is not available through the USB-C
port. When USB power is not sufficient and AUX PWR is not con-
nected, the channel 1 LCD display will flash with two dash (--)
characters.
Examples of GRAS products with a LEMO connection are:
•46BH½″LEMO Pressure Microphone Set.
•46AF½″LEMO Free-Field Microphone Set.

5
2 | External Features
Figure 1 — LEMO and CCP power module features
LED Displays
There is an LED display for each microphone input on the module.
There are up to four LED displays on the power module, depending
on the model. Each LED display identifies a microphone input so an

6 | 12Bx Power Modules Instruction Manual
appropriate microphone can be selected for TEDS data acquisition.
Numbers are only displayed on the LED displays when using the
GRAS Mic Power Module App or Audio Precision APx500 software.
Microphone Inputs
There are up to four microphone inputs on a power module,
depending on the model. Power modules that use standard power
come with LEMO connectors for the inputs. Power modules using
CCP come with BNC connectors for the inputs. The corresponding
output connectors are on the rear panels.
Power Module Outputs
There are up to four output connectors on a power module,
depending on the model. BNC connectors are used for all outputs.
Ground Lug
For Operator Safety when using power modules equipped with 7-
Pin LEMO Microphone input connectors, the ground terminal
marked with the Protective Earth Terminal symbol must be
connected with a low-resistance ground strap to a suitable ground.
See Protective Earth Terminal on page 36 for more information.
For CCP power modules, performance may be improved by con-
necting the ground lug of the power module and the APx analyzer
or other measurement equipment using a low-resistance ground
strap.
PC / Power Interface USB-C Port
The 12BA, 12BB and 12BE are powered through the USB-C port on
the rear panel of the module when connected to a USB 2.0 or USB
3.0 port and draw a maximum of 500 mA. Since the modules do not
affect gain or attenuation, there are no external switches or con-
trols. The USB-C port also serves as the data connection to the PC
when using with the GRAS Mic Power Module App or APx500 soft-
ware. USB 2.0 and USB 3.0 connections are supported.

7
Aux Power
LEMO modules have an auxiliary power input on the back of the
module that can be used when available USB ports are not able to
provide the minimum of 1.5 A required for operation. When the
module is connected to a USB port that does not supply at least
1.5 A, the LEDs for the first channel will flash “- -” and the module
will not provide power to connected microphones. CCP modules do
not have an auxiliary power option.
Note: Use the external power adapter provided (part number 4540.1805)
when AC mains power is required. The use of other power adapters is not rec-
ommended and may cause safety hazards.
Figure 2 — 12BB CCP 4-Channel Microphone Power Module
Mounting Tabs
Modules have four mounting tabs that can be used to anchor the
module with user-supplied fasteners to prevent any undesirable
movement. The module can be rack mounted using a rack cradle
(not included) or mounted directly to a work surface.
2.1 CCP Preamplifier Support
For CCP preamplifiers, the 12BA, 12BB and 12BE provide:
• A constant current supply (4 mA ) sourced at 24 V DC per
channel.
• Access to TEDS data (when used with the Mic Power Module
App or Audio Precision APx500 software).

8 | 12Bx Power Modules Instruction Manual
2.2 Input/Output
Microphones providing the input signals are connected via BNC or
LEMO connectors on the front panel of the power module. Output
signals from the power module rear panel are connected via BNC
connectors to the measurement system.

9
3|Operation
GRAS 12BA-12BF Power Modules are USB-powered pass-through
devices that provide power to measurement microphones and
integrate with the APx family of Audio Precision analyzers. The
power modules are available in one-, two- and four-channel con-
figurations to power up to four microphones. If more than four
microphones are required, multiple power modules can be used
concurrently. Additionally, Transducer Electronic Data Sheet
(TEDS) data can be read from TEDS-enabled microphones when
connected to a system running APx500 software or when using
the Mic Power Module App.
3.1 Channel Indicators and Assignment
Channel indicators are only enabled when using Audio Precision
APx500 measurement software or the GRAS Mic Power Module
App.
Each input connector on a power module has an LED channel indi-
cator on the front panel above the measurement microphone con-
nector. Channels are assigned dynamically when Audio Precision
APx500 measurement software starts and recognizes an attached
supported GRAS power module, or when the list command is used
in the GRAS Mic Power Module App with a supported GRAS power
module. Once assigned, the number is displayed on the LED chan-
nel indicator. Until a channel is assigned, the display will read “--”.
The microphone channels are used to identify attached measure-
ment microphones to acquire TEDS data and set sensitivity values.
3.2 TEDS Support
The APx500 software and Mic Power Module App can read TEDS
0.9 and TEDS 1.0 data from TEDS-enabled microphones connected
through supported GRAS power modules.

10 | 12Bx Power Modules Instruction Manual
For R&D testing, the data is used as data-sheet values in calibra-
tion reports. For production testing in controlled production setups
and environments, the TEDS data can be used in lieu of actual cali-
bration values.
For best accuracy, it is recommended that microphone sensitivity
be measured using an external acoustic source such as a piston-
phone.
TEDS is described in detail in the IEEE 1451 family of standards.
3.3 SysCheck2 Support
The APx500 software and Mic Power Module App supports
SysCheck2 functionality when combined with SysCheck2-enabled
microphones, such as the GRAS 246AE ½″Free-field SysCheck2
Microphone Set and the GRAS 246AO ½″Pressure Standard
SysCheck2 Microphone Set.
SysCheck2 is a GRAS-patented technology for verifying measure-
ment chain integrity. When set up, this verification tool can per-
form remote health checks on microphones, channel gain and
cable integrity. SysCheck2-enabled microphones can also provide
on-demand environmental data (temperature, barometric pressure
and humidity).
3.4 Input/Output Functions
The Microphone Power Module is a pass-through device that pro-
vides power to the microphone without signal degradation, gain
modification, or attenuation. The microphone inputs are on the
front of the device and the outputs to the analyzer are on the back
of the device. A USB-C port on the back of the device connects to a
PC for power and communication with APx500 measurement soft-
ware or Mic Power Module App.

11
3.5 Connection and Configuration
3.5.1 To connect the GRAS Power Modules
The power module connects to a USB 2.0 or USB 3.0 port on the PC
and a USB-C port on the back of the power module. For power
modules that provide CCP, power is provided to the module
through the USB cable; the module does not need to be plugged in
to mains power. For power modules that provide Standard Power
through a LEMO connection, the modules have an auxiliary power
connector that can be plugged into mains power if the USB con-
nection does not support the 1.5 A required by the power module.
There are no external switches or controls on CCP or Standard
Power (LEMO) Power Modules.
3.5.2 To configure the GRAS Power Module:
1) Connect the PC/Power Interface USB-C port to an available
USB 2.0 or USB 3.0 port on the measurement PC.
2) Connect the measurement microphone to the BNC or LEMO
input on the front panel of the power module.
3) Connect the measurement equipment to the corresponding
BNC output on the rear panel of the power module.
Note: In some situations, noise performance can be improved by
connecting the ground lugs of the power module to the ground
lug of the attached analyzer using a short, low-resistance
cable.
Once connected, microphone sensitivity can be acquired from a
TEDS-enabled microphone or can be measured using an external
acoustic source such as a pistonphone, and measurements can be
made using the attached measurement equipment.

12 | 12Bx Power Modules Instruction Manual

13
4 | Accessing TEDS Data
4.1 Setting up for TEDS Data
Channel assignment and TEDS data acquisition requires either the
GRAS Mic Power Module App or Audio Precision’s APx500 mea-
surement software running on the connected PC. The GRAS Mic
Power Module App and the APx500 measurement software can
communicate with the microphone power module using a USB 2.0
interconnection through the module’s USB-C connector. See the
following sections of this document or the APx500 User’s Manual
and the embedded help within the APx500 software for informa-
tion about channel assignment and TEDS data.
When used with the GRAS Mic Power Module App or an APx
analyzer:
• Microphone input channels are assigned and channel numbers
are displayed on the front panel LED displays above the
measurement microphone BNC input connectors.
• TEDS data can be read from TEDS-enabled microphones.
• Input channels for microphones can be accessed from Signal
Path Setup or through sequence steps in the APx500 software.
When multiple power modules are attached to a PC, the power
module with the lowest serial number will have channel 1 assigned
to the first channel and additional channels will be assigned incre-
mentally across all attached power modules, with the power mod-
ule with the highest serial number configured last. This process is
run when the APx500 software is launched or each time a com-
mand is entered in the Mic Power Module App.
NOTE: To maintain channel assignments when using APx500 software to
access TEDS data and set sensitivity levels, power modules should not be
added or removed from a test setup without closing and then relaunching
the APx500 software.

14 | 12Bx Power Modules Instruction Manual
4.1.1 Acquiring TEDS Data Using the Mic Power
Module App
The Mic Power Module App is a command-line program that runs in
a Command Prompt window in Microsoft Windows 10 or later. The
program can be used to view power module information and
acquire TEDS data when connected to a TEDS-enabled micro-
phone. The TEDS data is displayed in the command window and
can be written to a CSV file. Power module information available
includes serial number, product ID, available connectors, input
assignments, and version information. You can see which connec-
tor has a TEDS-enabled microphone attached, and view the model,
brand, and serial number.
PC System Requirements
The Mic Power Module App requires a PC running Microsoft Win-
dows 10 (64-bit) or later and one or more available USB 2.0 or USB
3.0 ports.
Installing the Mic Power Module App
The installation file (MicPowerModuleAppSetup.exe) can be down-
loaded from the Audio Precision website (www.ap.com/download/
gras-12bx-mic-power-module-app/).
To install the GRAS Mic Power Module App, download and then
double-click on the install file to start the installation. Follow the
instructions in the installation dialogs. The default installation
directory is:
C:\Program Files\GRAS\Microphone Power Module\
Once the installation is completed, to scan for connected power
modules and assign connector IDs, open a Command Prompt win-
dow, navigate to the installation directory and type:
MicPowerModuleApp.exe list

15
Running the Software
Run the GRAS Mic Power Module App in a Command Prompt win-
dow from the installation directory by typing the app executable
name (MicPowerModuleApp.exe) followed by a command name
and options and arguments.
All commands are case-sensitive and most require an input (port)
number to identify the port attached to the microphone. The port
number is specified using one of the following syntax options:
--InputNumber portnumber
-iportnumber
Note: When using the long option (--InputNumber) with commands, two
hyphens are used as a prefix and a space is required between the option and
the argument. When using the short option (-i) with commands, only one
hyphen is used and there is no space between the option and the argument.
The following commands and options are available:
list
Syntax
list [-t | --help | --version]
Description
The list command scans for connected power modules, assigns
connector ID numbers and shows connected power modules
(Serial Number, Inputs, and assigned connector ID numbers).
The assigned connector ID numbers are displayed on the LED
display above each connector.
Options
-t
The -t option displays the make, model, serial number and
connection ID of all TEDS microphones connected to the
power module. This option is not required and does not take
any arguments.
--help
The --help option displays help for the specified command
that precedes it.

16 | 12Bx Power Modules Instruction Manual
--version
The --version option displays the app version information.
Example
>MicPowerModuleApp.exe list
SN:00115, Bnc4X Inputs:[1,2,3,4]
teds
Syntax
teds -iportnumber | --InputNumber portnumber
[-o path\filename] | --help | --version]
Description
The teds command reads TEDS data from the microphone on the
specified Mic Power Module port. The -i or --InputNumber
option with the portnumber argument must be specified.
Example
>MicPowerModuleApp.exe teds -i1
Manufacturer ID|24
Manufacturer Name|GRAS Sound & Vibration
Model Number|46
Version Letter|1
Version Number|5
Serial Number|265867
Template ID|27
Sensitivity @ reference
condition|0.0492436116918724
Reference frequency (F ref)|249.847411747693
Polarization Voltage|Pre-polarized
Microphone Type|Free field
Microphone Size|1/2 inch
Equivalent microphone volume|4E-08
Polarity (Sign)|negative
Transducer Electrical Signal Type|Voltage Sensor
Mapping Method|Linear
AC or DC Coupling|DC
Calibration Date|09/12/2019