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Automatic Serial Data Collection

Automatic Serial Data CollectionAs more and more devices come equipped with some type of communication for data collection and monitoring, the amount of data that can be collected by a PC in a system is astounding. A problem arises, however, when multiple instruments or devices need access to the PC through the serial port, but only one port is available.
There are multiple options for expanding the capability of a port that was designed to communicate with only one device. You can add a separate serial port for each RS-232 device that you need to talk to. By adding serial ports, multiple devices can have their own dedicated port, often concurrently and at high speeds. The drawback is that separate serial ports may be expensive and require some effort to configure. There is also a practical limit on resources available inside the PC to allocate to Serial Ports.
Multiple devices can be tied together by converting the signal at each point to a multi-drop bus, like RS-485. This allows up to 32 devices on a single network without repeaters. The devices can also be connected up to 4000 feet away from the PC. The disadvantage is that each device must have its own unique address. Also, some protocol needs to be established to prevent more than one device at a time from sending data to the PC. Usually this is done by having the PC poll each device individually. This does not lend itself well to devices that send their data automatically, without being requested.
Using the 232BSS4 buffered Smart Switch is an excellent way to collect data from multiple devices utilizing RS-232 serial ports. Up to four instruments, card readers, or time clocks can be directly connected to the 232BSS4, providing access through a single serial port on your PC.
If you have more than four devices that are sending data, more than one 232BSS4 can be cascaded, allowing more ports to be added. The 232BSS4 buffers data from all ports at once, making it well suited for devices that will send a fixed amount of data at sporadic intervals, such as measurement instruments, security access card readers, barcode scanners, or time clocks. Below is an explanation of how best to utilize the 232BSS4 to connect these devices to your PC.>

Figure 1
>Figure 1 shows a typical setup, with 16 devices sending information at random times to the PC. The switches at Level 2 receive the data and send it on to the Level 1 switch. The Level 1 switch buffers the data and sends it to the PC. Each of the switches will automatically send the data when it is available. If another port has access to the PC, the data will be buffered until a path is available.
Cascading in Automatic mode:
For best results in an automatic system, the 232BSS4s in the system should be set up the following way.

  • Set the switches to turn on the AutoSelect feature.
  • Set the Port Timer to 0
  • Set the Inactivity Timer on all of the switches to somewhere between 50 and 500 milliseconds, depending on the space between data packets and the response time required to each connected device.
  • If you need your software to identify which port sent the data, set up the port preamble on the Level 2 switches. Set each port to have a unique preamble. The preamble can be 1, 2, 3, or 4 characters long, and any characters can be used. The preamble will be added to the beginning of each new data packet arriving at the PC. The data collection software on the PC should be written to recognize this preamble as an address or identifier of the data source.
Cascading in Polled Mode
This configuration will also work with systems where the devices have to be polled for information. With the setup of Figure 1, the switches can be configured so that you still only have to send one set of switching characters. To do this, set the switches up in the following way:
  • Set the switch on Level 1 to broadcast to all slaves on startup.
  • Set the switch on Level 1 to AutoSelect mode, no preamble.
  • Set the switch on Level 1 for 0 Port Time
  • Set the switch on Level 1 for a short Inactivity Time. Somewhere around 5 milliseconds or so.
  • Set the switches on Level 2 for no AutoSelect.
  • Set the preamble on the Level 2 switches to be unique from each other. One suggestion is to use a 3 character command. Use the first character as a start of command character like STX. The second character could represent the address of the Level 2 switch you are going to. The third character is the command character.

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My 2004 buick rainer is stuck in park but dash board says its in drive how can i fix this


Automatic Transmission Shift Lock Control System
The automatic transmission shift lock control system is a safety device that prevents an inadvertent shift out of PARK when the engine is running. The driver must press the brake pedal before moving the shift lever out of the PARK position. The system consists of the following components:
?€¢
The automatic transmission shift lock control solenoid


?€¢
The automatic transmission shift lock control switch
Can you or can you not take it out of park ?
Shift Lever Does Not Move with Brake Pedal Depressed
yes or no ?
PRND321 Display
The instrument panel cluster (IPC) displays the selected gear position as determined by the engine control module (ECM). The IPC receives a serial data message from the ECM indicating the gear position. The PRND321 display blanks if:
?€¢
The ECM detects a malfunction in the transmission range switch circuit.


?€¢
The IPC detects a loss of serial data communications with the ECM.


You have a transmission range sensor or PCM problem , Need a professional grade scan tool to diagnose the problem , well that would be the easiest way to test .You should have all modules test for DTC'S - diagnostic trouble codes ! That would point you in the right direction ! I would suggest you google class 2 serial data communication network !

Aug 17, 2015 | Buick Cars & Trucks

1 Answer

2000 buick lesabre leveling compressor won't turn on I took off n hooked to battery and works that way I checked all relays and fuses and there good


This is the way you start diagnosing this system !
Automatic Level Control Diagnostic System Check
Install a scan tool. Does the scan tool power up?
Go to Step 2
Go to Scan Tool Does Not Power Up in Data Link Communications

2
  1. Turn ON the ignition, with the engine OFF.
  2. Attempt to establish communication with the Rear Integrated Module (RIM).
Does the scan tool communicate with the RIM?
Go to Step 3
Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications
Select the automatic level control display DTC function on the scan tool.
Does the scan tool display any DTCs?
Go to Step 4
Go to Symptoms

4
Does the scan tool display any DTCs which begin with a "U"?
Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Connector Diagnosis
Go to Step 5

5

Does the scan tool display DTC B1007 or B1009?
Go to Diagnostic Trouble Code (DTC) List/Type in Body Control System
Go to Step 6

6

Does the scan tool display DTC B1327?
Go to Diagnostic Trouble Code (DTC) List/Type in Engine Electrical
Go to Diagnostic Trouble Code (DTC) List/Type
This is one you should take to a ASE certified repair facility , there are electronic modules involved you have no idea about !

May 16, 2015 | 2000 Buick LeSabre

1 Answer

I have 08 ford escape when I try to scan it said no communication


Do you know about communication networks or serial data communications on vehicles , these let the scan tool communicate with the different modules on the vehicle ! Newer vehicles have several, PCM - powertrain control module , Anti-theft module , Air bags , antilock brakes , Body control module or in the case of ford a smart junction box . an some others !
Communications Network Vehicle communication utilizes both International Standards Organization (ISO) 9141 and controller area network (CAN) communications. ISO 9141 is used for diagnostic use only, and CAN is used for many modules to communicate with each other on a common network. CAN in-vehicle networking, is a method for transferring data among distributed electronic modules via a serial data bus. Without serial networking, intermodule communication requires dedicated, point to point wiring resulting in bulky, expensive, complex, and difficult to install wiring harnesses. Applying a serial data network reduces the number of wires combining the signals on a single network. Information is sent to the individual control modules that control each function.
The vehicle has 3 module communication networks:
  • ISO 9141
  • Medium speed (MS) CAN
  • High speed (HS) CAN
All 3 networks are connected to the data link connector (DLC). This makes diagnosis and testing of these systems easier by allowing one scan tool to be able to diagnose and control any module on the 3 networks from one connector. The DLC can be found under the instrument panel between the steering column and the audio unit.
HS-CAN Network Operation
The HS-CAN network communicates using bussed messages. The HS-CAN network uses an unshielded twisted pair cable, data bus (+) and data bus (-) circuits. In addition to scan tool communication, this network allows sharing of information between all modules on the network.
The HS-CAN is a high speed communication network used for the following modules:
  • ABS module
  • 4WD control module (if equipped)
  • Instrument cluster
  • PCM
  • MS-CAN Network Operation
    The MS-CAN network communicates using bussed messages. The MS-CAN has an unshielded twisted pair cable, data bus (+) and data bus (-) circuits. In addition to scan tool communication, this network allows sharing of information between all modules on the network.
    The MS-CAN is a medium speed communication network used for the following modules:
    • Instrument cluster
    • SJB
    HS-CAN Network
  • What type of scan tool are you using ? or are you using a code reader ?

  • What
Computer No Communication Troubleshooting by Wells Saturn Toyota Echo No Communication Case Study

Mar 18, 2015 | 2008 Ford Escape

1 Answer

97 buick century has no data from OBD2 scanner.


The protocol is class 2 . Maybe your code reader is no good .
012 GM Class II Communications

Data Link Connector (DLC)
The data link connector (DLC) contains the following serial data links:
• Class II
• Entertainment and Comfort (E&C)
The DLC also provides a power source for the scan tool as follows:
• Unswitched voltage (B+) at DLC terminal 16 (circuit 1450)
• Ground at terminal 4 (circuit 1450) and terminal 5 (circuit 1550)

Class II Serial Data Link
The class II serial data link allows the following modules to communicate data with each other:
• Body control module (BCM)
• Electronic brake traction control module (EBTCM)
• Heater-A/C control (if equipped with RPO CJ2)
• Instrument panel cluster (IPC)
• Powertrain control module (PCM)
• Inflatable Restraint Sensing and Diagnostic Module (SDM).
The Class II serial data link allows a Scan Tool scan tool to communicate with the above modules for diagnostic and testing purposes. The Class II serial data link is located at the DLC connector terminal 2. Terminal 2 consists of the following circuits:
• Circuit 1036
• Circuit 1037
• Circuit 1128
• Circuit 1049
• Circuit 1122
• Circuit 1132
Entertainment and Comfort (E&C) Serial Data Link
The entertainment and comfort (E&C) serial data link allows a scan tool to communicate with the radio or the mobile telephone handset the remote CD player (if equipped). This communication is for diagnostic and testing purposes. The E&C serial data link is located at the DLC connector terminal 14, circuit 835.
PIN #9 goes to the air bag module .

Aug 04, 2017 | 1997 Buick Century

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