User's Manual
Table Of Contents
- Health Limits
- Contents
- Before You Begin
- Developing the Installation Site Plan
- Installing and Configuring the MPI 6000
- Lane Tuning Guidelines
- Optimizing MPI 6000 Reader System Performance
- General Software Information
- Configuration Commands and Responses
- Configuring the MPI 6000
- Required Commands to Set Up MPI 6000 Reader
- System Interface Command Group Commands
- System Identify
- Set Communications Baud Rate
- Get Communications Baud Rate
- Set Time and Date
- Get Time and Date
- Firmware Download
- Reset Reader
- Get Stored Tag Response Message
- Get Number of Stored Tag Response Messages
- Delete All Stored Tag Response Messages
- Get System Startup Status
- Get Lane Controller Interface Status
- Get System Interface Status
- Get DigBrd Hdwr Remote Inventory
- Get DigBrd CPU Boot Fmwr Remote Inventory
- Get DigBrd CPU Appl Fmwr Remote Inventory
- Get DigBrd FPGA UDP/IP Core Fmwr Remote Inventory
- Get UDP/IP Core Lane Controller Parameters
- Set UDP/IP Core IP Address
- Get UDP/IP Core IP Address
- Get UDP/IP Core Port Number
- Configuring the MPI 6000
- Tag Command Processing
- System Diagnostics and Preventive Maintenance
- Acronyms and Glossary
- Block Diagrams
- System Technical Specifications
- Hardware Interfaces
MPI 6000 Multi-Protocol Reader System Guide
4-4
• Maximum traffic speed in the lane, which is used to determine the required length
of the capture zone; also known as the footprint
• The type of lane, that is, express or mixed-use lane
• The presence of vehicle framing devices such as light curtains, which may dictate
the desired location of the first read point
• The presence of alternate toll collection devices, such as coin machines in mixed-
use lanes, which may dictate the desired first read point
• The width of the lane
Traffic requirements are further defined by two terms, tag transaction or handshake
and capture zone or lane footprint.
Tag Transaction or Handshake
A handshake is defined as one complete transaction between a tag and the AVI equip-
ment. The handshake is defined as a complete transaction because in many cases the
transaction consists of more than a simple read. The transaction may be a read com
-
mand followed by a general acknowledgment (GENACK), or a read command fol-
lowed by a write command followed by a GENACK, or some other complex sequence
of commands. Each part of the handshake requires time, and the transaction with the
tag cannot be considered complete unless all the components have been completed. To
this end, there will be a minimum time associated with the handshake. It may be as lit
-
tle as a few milliseconds, or as high as 30 milliseconds or more.
Capture Zone or Lane Footprint
The footprint is the length of the capture zone measured on the pavement, starting at
the point of the first tag read and ending where tag reads stop, typically three or four
feet past the receive antenna (
Figure 4-1). This value is based on the actual measure-
ments of the capture zones of at least five diversely different vehicles equipped with
properly mounted tags. Ideally, RF margin plots taken at the time the footprint are
measured on a foot-by-foot basis, but for the basic measurements discussed in this
guide, all that is needed is the total footprint length from first read to last read.