MCC iPort/AI 2 RS-232 to I2C host adapter with Circuit... User manual

User’s Guide
ASCII Interface
RS-232 to I2C Host Adapter
with Circuit Sense™
www.mcc-us.com

Introduction
The MCC iPort/AI 2™ RS-232 to I2C Bus host adapter with Circuit Sense allows
any Windows, Linux, or Mac OS X host computer to become an I2C Master or
Slave device, transmitting or receiving I2C messages between the host computer and
one or more I2C devices across an I2C Bus.
This user’s guide describes the installation and operation of the iPort/AI 2 host
adapter, and the RS-232 and I2C Bus interconnects. Also described are the iPort
Utility Pack software for quick I2C Bus communication, MS.Net and LabVIEW
libraries for custom software development, and other tools and applications.
A complete set of resources for the iPort/AI 2 is available at:
www.mcc-us.com/iPortAI-2
This product conforms to the I²C Bus specifications defined by NXP/Philips
Semiconductors.
To find out more about I2C, we suggest you review our white paper “I2C Bus
Technical Overview” at:
www.mcc-us.com/I2CBusTechnicalOverview.pdf.
I²C is a trademark of NXP (Philips) Corporation. All trademarks acknowledged as
the property of their owners.
01-NOV-2018

Copyright© 2018 by Micro Computer Control Corporation. All rights reserved. No
part of this publication may be reproduced by any means without the prior written
permission of Micro Computer Control Corporation, PO Box 275, Hopewell, New
Jersey 08525 USA.
DISCLAIMER: Micro Computer Control Corporation makes no representations or
warranties with respect to the contents hereof and specifically disclaims any implied
warranties of merchantability or fitness for any particular purpose. Further, Micro
Computer Control Corporation reserves the right to revise the product described in
this publication and to make changes from time to time in the content hereof
without the obligation to notify any person of such revisions or changes.
WARNING - Life Support Applications: MCC products are not designed for use
in life support appliances, devices, or systems where the malfunction of the product
can reasonably be expected to result in a personal injury.
WARNING - Radio Frequency Emissions: This equipment can radiate levels of
radio frequency energy that may cause interference to communications equipment.
Operation of this equipment may cause interference with radio, television, or other
communications equipment. The user is responsible for correcting such interference
at the expense of the user.
WARNING - Electrostatic Discharge (ESD) Precautions: Any damage caused by
Electrostatic Discharge (ESD) through inadequate earth grounding is NOT covered
under the warranty of this product. See the “Electrostatic (ESD) Precautions”
section of this guide for more information.
Electronic Waste Notice - This product must NOT be thrown into general waste,
but should be collected separately and properly recycled under local regulations.
Created in the United States of America

Table of Contents
1 Overview .......................................................1
iPort/AI 2 Product Features .........................................2
iPort/AI2PackageContents ........................................3
SystemRequirements .............................................4
2 Interconnects ....................................................4
RS-232 Serial Port Connector .......................................4
DB-25 Serial Port Pinout ........................................4
DB-9 Serial Port Pinout .........................................4
iPortPower .....................................................5
Viathepowerjack .............................................5
Via the I2C interface connector ....................................5
I2C Mini Interface Connector .......................................5
3 HardwareConfiguration ...........................................6
CircuitSense ....................................................6
PowerSourceMode ............................................6
VoltageSenseMode ............................................6
I2CBusPull-upResistors ..........................................7
ConnectingtoaLow-VoltageTargetSystem ...........................7
ConnectingtoanSMBusTargetSystem...............................7
4 ESD (Electrostatic Discharge) Precautions .............................8
Host Computer Grounding .........................................8
Case1-DesktopandSingle-boardComputers........................8
Case2-LaptopComputers.......................................9
Grounding Solutions ..............................................9
5 HardwareSet-Up.................................................9
SerialPortConnection............................................10
I2CBusConnection ..............................................10
PowerConnection ...............................................10
6. Software Support ................................................10
I2C Bus Communication Utilities ...................................10
iPort Utility Pack for Windows ...................................10
iPortMessageCenter ........................................11
iPortMessageManager ......................................11

iBurner I2CBusEEPROMProgrammer............................11
I2CBusSoftwareDevelopmentTools................................11
MS.NETClassLibrary .........................................11
LabVIEWVILibrary ..........................................12
ASCIICommandInterface ......................................12
iPort/AI2RevisionReport...........................................13
AdditionalInformation..............................................13
Appendix A - I2CConnectorInformation ...............................14
Declaration of Conformity ...........................................15
FCCStatement..................................................15
CE Declaration of Conformity ......................................15

1
1 Overview
The MCC iPort/AI 2 (#MIIC-212), RS-232 to I2C Bus Host Adapter with ASCII
Interface and Circuit Sense, allows any PC, Host Computer, PLC, or Single Board
Computer with a legacy or add-on serial port to become an I2C Master or Slave
device, transmitting or receiving I2C messages between the Host Computer and one
or more I2C devices across an I2C Bus.
Circuit Sense, our I2C Bus voltage sensing technology, allows the iPort/AI 2 to
work with the latest I2C Bus devices at voltages as low as 0.5 volts.

2
iPort/AI 2 Product Features
• OS Support: Windows, Linux, Mac OS X, and many more.
• Host Support: Any Computer with a legacy or add-on RS-232 Serial Port.
• High Performance Processor Increases Throughput (2x to 200x).
• External Power Jack or I2C Bus Powered (+5VDC).
• Built-in ESD, Over-voltage, and Reverse-voltage Protection.
• Switch Controlled Properties:
•I
2C Bus Power Source (5v@100ma).
•I
2C Bus Voltage Sense (0.5v to 5v, Enable or Disable).
•I
2C Bus Pull-Ups (1.8K ohm, Enable or Disable).
• Software Controlled Properties:
•I
2C Bus Master Clock Rates: 100KHz (Fixed)
•I
2C Bus General Call (Enable or Disable).
•I
2C Bus Time-Out (1000 milliseconds) (Fixed)
• Host Communication Flow Control (XON/XOFF or RTS/CTS)
• User Interface Echo/Prompt (Enable or Disable).
• User Data Format (HEX or ASCII/HEX)
• Supported I2C Bus Activities:
• Master and Slave Functions
• Transmit, Receive, and Tx/Rx Data Functions
• Multi-Master Arbitration Loss Detection
• Clock-stretch Detection
• Bus Time-Out Detection
• 7-bit Slave Address Generation and Detection
• Up to 32K data bytes in a single message
• Software Support:
• Free Application Software (Master, Slave, and EEPROM Programmer).
• Software Development Tools (MS.NET, LabVIEW, and ASCII Commands).
• Compatible with existing iPort/AI applications.
• US-FCC and EUR-CE EMC Compliant.
• RoHS/Lead-Free Compliant.

3
iPort/AI 2 Package Contents
The iPort/AI 2 package includes the following items:
• iPort/AI 2, RS-232 to I2C Bus Host Adapter.
•I
2C Bus Mini Clip-lead Cable (4-wire, 1 ft.).
• DB-9F to DB-25M Serial Port Adapter Cable (1 ft.).
• Global 5VDC Power Supply.
• iPort/AI 2 Quick Start Guide.
• iPort/AI 2 Travel Case.
• Online Items*
• iPort/AI 2 Datasheet
• iPort/AI 2 User’s Guide (this document)
• iPort Utility Pack Software
• Application Software.
• Software Development Tools
(* www.mcc-us.com/iPortAI-2)

4
RS-232 Serial Port Connector
System Requirements
a. A host computer with one free legacy or add-on RS-232 port.
b. Windows XP OS or higher to run iPort Utility Pack applications.
2 Interconnects
The iPort/AI 2 includes three (3) interconnections:
RS-232 Serial Port Connector
The RS-232 connector provides connection from the I2C adapter to the serial port
on the host computer. For computers with DB-9 connectors, use the DB-9 to DB-25
(#C9F25M1) cable provided with the adapter, or equivalent.
The I2C adapter implements the RS-232 interface using the following pins:
DB-25 Serial Port Pinout
DB-25 Pin 2, Transmit Data from the Host Computer to the iPort
DB-25 Pin 3, Receive Data from the iPort to the Host Computer.
DB-25 Pin 4, Request to Send from the Host Computer to iPort.
DB-25 Pin 5, Clear to Send from the iPort to the Host Computer.
DB-25 Pin 7, Ground between Host Computer and iPort
DB-9 Serial Port Pinout
DB-9 Pin 3, Transmit Data from the Host Computer to the iPort
DB-9 Pin 2, Receive Data from the iPort to the Host Computer.
DB-9 Pin 7, Request to Send from the Host Computer to iPort.
DB-9 Pin 8, Clear to Send from the iPort to the Host Computer.

5
DB-9 Pin 5, Ground between Host Computer and iPort
iPort Power
The I2C adapter requires 50ma of REGULATED +5 volt power. This power can be
supplied in one of two ways:
• Via the power jack.
If the I2C adapter is powered via its +5VDC power jack, and the adapter is
operating in power SOURCE mode, excess power is available via the +V wire in
the I2C connector to power external devices.
• Via the I2C interface connector.
If 50ma of regulated +5V power is available in the target system, and the adapter
is operating in power SOURCE mode, the I2C adapter can be powered via the +V
wire in I2C interface connector.
I2C Mini Interface Connector
The iPort/AI 2 I2C Bus host adapter includes a five wire (1x5) 2.54 mm (.100"),
positive locking, shrouded header receptacle connector (see Appendix A) for
interfacing to an external I2C Bus. Interface lines provided include:
•I
2C Clock (SCL)
•I
2C Data (SDA)
• /INT (Not Used)
• Ground
• +V (optional)
Minimum wiring for I2C Bus communications include I2C Bus Clock, Data, and
Ground. Use of the +V wire in the I2C Interface connector are user optional.
NOTE: See the Hardware Configuration section below for additional information
on configuring the I2C Bus interface.

6
I2C Bus Mini Interface Receptacle
Mini Interface Receptacle Pinout
I2C Bus Mini-Clip-Lead cables are available to connect the iPort/AI 2 adapter to a
target system. Each clip-lead is identified (White=C=SCL, Red=V=+V,
Green=D=SDA, Black=G=Ground.
I2C Bus Mini-Interface cables with two Mini Interface plugs are also available to
connect the I2C adapter to an external I2C Bus.
3 Hardware Configuration
Circuit Sense™
The iPort/AI 2 includes MCC’s Circuit Sense technology. Circuit Sense allows the
I2C interface +V wire can operate in two modes, Power Source Mode and Voltage
Sense Mode. Mode selection is controlled by the MODE slide switch on the side of
the unit enclosure.
Power Source Mode - The +V wire can supply power (5v @ 100 mA) Vcc to an
external I2C Bus system. In Power Source Mode, the voltage of the iPort/AI 2 SCL,
and SDA internal pull-ups, if enabled, and Voltage Sense circuit (0.3Vcc LowMAX,
0.7Vcc HighMIN) is connected to the adapter’s +5v power supply. (Use of the +V
wire in Power Source Mode is user optional).
Power Source Mode is similar to the standard mode of operation on earlier versions
of MCC I2C Bus host adapters.
Voltage Sense Mode - The +V wire is connected to the external I2C Bus system
pull-up supply voltage (0.5v to 5v) Vcc, and automatically adjusts iPort/AI 2 SCL,
SDA, and /INT Voltage Sense circuit levels to match (0.3Vcc LowMAX, 0.7Vcc

7
HighMIN). In Voltage Sense Mode, the voltage of the iPort/AI 2 SCL, SDA, and
/INT internal pull-ups, if enabled, is equal to the external voltage (Vcc) applied to
the +V wire. (Use of the +V wire in Voltage Sense Mode is required).
I2C Bus Pull-up Resistors
I2C Bus systems are based on open-collector technology requiring pull-up devices
on each signal wire (SCL, SDA, /INT). These pull-up devices usually take the form
of pull-up resistors connected to bus power.
The I2C adapter includes a PULL-UPS slide switch used to enable or disable
internal 1.8K ohm pull-up resistors attached to the SCL, SDA, and /INT lines.
Every I2C Bus system must have at least one pull-up on the signal lines. In some
cases, the pull-ups may be present in the external I2C Bus circuit. Use this switch to
configure the pull-up resistors for your system.
Connecting to a Low-Voltage Target System
If you are connecting the I2C adapter to a low-voltage (<5v) target system, you
should follow these steps BEFORE applying power:
• Using the adapter MODE slide switch, put the adapter is Sense Mode.
• If you target system does NOT supply I2C Bus pull-ups, use the adapter PULL-
UPS slide switch to enable the adapter’s internal 1.8K ohm pull-ups.
• Connect the I2C connector +V wire to the target system I2C Bus power. The I2C
adapter will be powered from its own +5V power supply, and adapters pull-ups, if
enabled, and Voltage Sense circuit will be powered by the target system’s low-
voltage power supply.
Connecting to an SMBus Target System
If you are connecting the I2C adapter to a SMBus target system, you should follow
these steps BEFORE applying power:
• Shut off the I2C adapter’s internal pull-ups (See Pull-up Resistor section).
• Use external SMBus rated (approx. 15k ohm) pull-up resistors. These pull-ups
may already be present in the target system.

8
• Visit the I2C .vs. SMBus FAQ page (www.mcc-us.com/I2CSMBusFAQ.htm).
• See the SMBus Specification for additional details.
Special Note for SMBus Users: MCC’s I2C adapters are designed to be I2C Bus
compatible, not SMBus compatible. Some features of the SMBus protocol not
supported include time-outs, device reset, and Packet Error Check byte processing.
The non-supported SMBus features may, or may not, permit the use of the I2C
adapter in your SMBus application. Consult the MCC FAQ web page and SMBus
Specification for details.
4 ESD (Electrostatic Discharge) Precautions
Electrostatic discharge is defined as the transfer of charge between bodies at
different electrical potentials. Electrostatic discharge can change the electrical
characteristics of a semiconductor device, degrading or destroying it. Electrostatic
discharge also may upset the normal operation of an electronic system, causing
equipment malfunction or failure.
When connecting the I2C adapter to a host computer and a target system, extreme
care must be taken to avoid electrostatic discharge. Failure to follow ESD protection
procedures when using the I2C adapter could damage the host computer, I2C
adapter, or the target system, and void product warranty coverage.
Host Computer Grounding
Case 1 - Desktop and Single-board Computers. The chassis on a desktop or
single-board host computer must be connected to earth ground to comply with
safety regulations. If the computer chassis is NOT connected to earth ground for
some reason (i.e., use of a two-prong power mains plug), the host computer power

9
supply ground will float to some unknown voltage potential.
Case 2 - Laptop Computers. Laptop computers present special ESD problems. Most
laptop computers use an external double-insulated mains power supply which is
NOT connected to the mains earth ground. This means that the laptop chassis is
floating at some unknown voltage potential.
In either case, upon connection to the I2C adapter and the target system, the host
computer will discharge energy through its RS-232 port to the I2C adapter, and on
to the target system. This discharge could damage the host computer, I2C adapter,
and the target system.
Grounding Solutions
To avoid damage to the host computer, I2C adapter, or target system, follow these
instructions:
• Wear an earth grounded wrist strap, or discharge any static charge build-up, when
handling the I2C adapter or any target system devices.
• Ensure that both the host computer and target system are connected to a common
earth ground point.
• Make sure that all interconnections are made BEFORE applying power to the
host computer, I2C adapter, and target system.
• If you are using a laptop computer or host computer that is NOT connected to
mains earth ground, make a hard-wired connection from the host computer (i.e.,
RS-232 port D-connector shell) and the target system ground connector to a
common earth ground point.
• Avoid plugging and unplugging system components while the host computer or
target system is powered.
• Ensure that any devices connected to the target system are properly grounded to
the common earth ground point.
• If unsure how to properly ground system components, seek electrical expert help.
WARNING: Any damage caused by Electrostatic Discharge (ESD) through
inadequate earth grounding is NOT covered under the warranty of this product.
5 Hardware Set-Up
This section provides information on connecting the I2C adapter to your host
computer and I2C Bus target system.

10
Serial Port Connection
Attach the I2C adapter to a free legacy or add-on RS-232 port on your host
computer. If your RS-232 port has a DB9 connector, use DB-9F to DB-25M serial
port cable included with the I2C adapter.
I2C Bus Connection
Connect the I2C Bus mini clip-lead cable to the I2C adapter and your I2C device.
MCC also offers an I2C mini interface cables that are compatible with our adapters.
You may not need to, or want to, connect the +V wire to your target system. Refer
to the “+5VDC Power Jack” and “Hardware Configuration” sections for details on
pull-up resistors and connecting the optional +V wire.
Power Connection
Connect I2C adapter power via the power jack or I2C Bus connector. See “+5VDC
Power Jack” section for details.
If you have any questions on I2C adapter setup and configuration, please visit our
FAQ Page (http://www.mcc-us.com/faq.htm) or contact our technical support team
([email protected]).
6. Software Support
MCC offers the following categories of I2C Bus software support:
I2C Bus Communication Utilities
iPort Utility Pack for Windows
The iPort Utility Pack for Windows provides a quick-start to I2C Bus
communications. The Utility Pack includes two Windows-based application that
will help you get started sending and receiving I2C Bus messages quickly and
easily.

11
iPort Message Center
iPort Message Center is a bus master application with a spreadsheet-like user
interface. Each row in the spreadsheet represents a single I2C Bus message. A
message can transmit data to a specified slave device, or read data from a
specified slave device. Received data is automatically displayed in the
spreadsheet.
Message options include repeated-start, and a time delay after each message.
One or more messages in the spreadsheet are transmitted in sequence, and can
auto-repeat at the completion of the last message.
iPort Message Manager
iPort Message Manager is a bus master/slave application that can master
transmit, master receive, slave transmit, and slave receive I2C Bus messages.
Message options include master transmit and transmit/receive, and auto-repeat
iBurner I2C Bus EEPROM Programmer
iBurner is our I2C Bus EEPROM Programmer software package for Windows.
With iBurner, you can quickly and easily blank-check, program, read, and verify
a wide variety of I2C Bus EEPROMs. iBurner also supports scripting, allowing
EEPROM programing serialization and automation.
I2C Bus Software Development Tools
MCC provides three methods for creating custom application software for ASCII
Interface I2C Bus Adapters:
MS.NET Class Library
The MS.NET Class Library provides a comprehensive set of tools for the creation
of robust I2C Bus applications. Included are Constructors, Methods, Properties,
Events, Enumerations, and SampleCode for Visual Basic.NET, Visual C#, Visual
C++, Visual J#, and LabVIEW.

12
LabVIEW VI Library
The LabVIEW VI Library provides a complete set of low-level, mid-level, and
high-level Virtual Instruments (Vis) for the LabVIEW developer. Included are
VIs for establishing a connection to the Adapter, performing I2C Bus Master and
Slave operations, and Sample LabVIEW applications.
ASCII Command Interface
The ASCII Command Interface provides a direct low-level ASCII command
application program interface to the I2C Bus Adapter. ASCII commands can be
accessed from a terminal emulation program running on the host computer, or
from an application program using host computer operating system serial port
functions.
iPort/AI 2 software support and more is available at:
www.mcc-us.com/iPortAI-2

13
iPort/AI 2 Revision Report
This section defines revisions and changes made to the iPort/AI 2 interface:
Revision: 1.00
7. Initial Release
Additional Information
For additional information on the I2C Bus, please refer to the following:
“What is I2C?”
www.mcc-us.com/I2CBusTechnicalOverview.pdf
“Frequently Asked Questions (FAQ)”
www.mcc-us.com/faq.htm
"The I2C and How to Use It"
www.mcc-us.com/i2chowto.htm

14
Appendix A - I2C Connector Information
I2C Bus Interface Connector and Plug Information
The iPort/AI 2 uses the following 1x5 2.54 mm (.100") pitch, 0.64 mm (.025")
square pin, header and plug assemblies for the I2C Bus interface.
I2C Header Receptacle
Molex C-Grid® SL™ 70553 Header Molex Part # 70553-0004
I2C Plug Housing
Molex C-Grid® SL™ 70066 Crimp Housing Molex Part # 50-57-9405
Molex C-Grid® SL™ 70058 Crimp Terminal Molex Part # 16-02-0102
iPort/AI 2 I2C cables and other accessories are available online at:
www.shop-mcc-us.com

15
Declaration of Conformity
FCC Statement
DECLARATION OF CONFORMITY WITH FCC RULES FOR ELECTROMAGNETIC
COMPATIBILITY
We, Micro Computer Control Corporation, of 83 Princeton Avenue #1D / PO Box 275,
Hopewell, New Jersey 08525 USA, declare under our sole responsibility that the product:
iPort/AI 2 (#MIIC-212) and iPort/AFM 2 (#MIIC-213)
to which this declaration relates:
Complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions;
(1) this device may not cause harmful interference, and (2) this device must accept any
interference received, including interference that may cause undesired operation.
Test Laboratory Information:
MET Laboratories, Inc.
Test Report Number: EMC88332-FCC
Test Report Date: January 27, 2016
Technical file held by: Micro Computer Control Corporation, 83 Princeton Avenue #1D / PO
Box 275, Hopewell, New Jersey 08525 USA, or its applicable authorized distributor or
representative.
CE Declaration of Conformity
We, Micro Computer Control Corporation, of 83 Princeton Avenue #1D / PO Box 275,
Hopewell, New Jersey 08525 USA, declare under our sole responsibility that the iPort/AI 2
(#MIIC-212) and iPort/AFM 2 (#MIIC-213), to which this declaration relates, is in
conformity with EMC Emissions Standard for Information Technology Equipment
EN55022:2010, and EMC Immunity Standard for Electrical Equipment for Measurement,
Control and Laboratory Use EN 61326-1: 2013.
Test Laboratory Information:
CLASS Industries, Ltd.
Test Report Number: CI06074
Test Report Date: November 3, 2015
Technical file held by: Micro Computer Control Corporation, 83 Princeton Avenue #1D / PO
Box 275, Hopewell, New Jersey 08525 USA, or its applicable authorized distributor or
representative