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RS232 Support

Problem Programs

Two styles of programs that may cause interfere with the communication of the 1133A are identified.

  1. Palm Hotsync: If Hotsync is configured to connect to a device over the RS-232 port then Hotsync must be turned off before trying to connect to an 1133A because Hotsync software will not share the RS-232 port making it impossible to connect to an 1133A.
  2. Virus scanners: Virus scanners with real-time file monitoring features turned on may cause delays in receiving data. The PSCSV program creates a file on the computer hard drive and constantly writes to the created file during broadcasts or data downloads. If there is a large quantity of data the virus scanner cannot keep up with the data flow. The solution is to turn off the real-time file monitoring feature.

Bandwidth Limitations

The default baud rate for 1133's and PSCSV is set to 38400 (to minimize the serial driver problem below). This baud rate does not have enough bandwidth to download broadcast waveform data (see the table below).

Data Type Required Bandwidth (bytes/sec)
Basic Broadcast 24 - 244
Energy Broadcast 22 - 182
Harmonics Broadcast 92 - 2492
Phasor Broadcast 920
Summ Harm Broadcast 20 - 140
Waveform Broadcast 7960

Baud*Available Bandwidth (bytes/sec)
115200 11520
57600 5760
38400 3840
28800 2880
19200 1920
14400 1440
9600 960
* Assumes 8 Data bits, No Parity, 1 Stop Bit

Windows Serial Driver Support

The default Win32 serial drivers are not capable of reliably sustaining baud rates of 57600 or better. If PSCSV detects any hardware and or serial driver communication errors it updates the status bar thus:
status bar highlight of where comm errors are displayed
If you see RECV ERRs, then you should configure your unit to use a lower baud rate.

Changing an 1133's baud rate

  1. Using the current connection, configure the unit's comm ports (Connection, Configure, Communication Ports).
  2. Change the baud rate on the correct port.
  3. Click OK.
  4. Close the current connection (Connection, Close).
  5. Create a new RS232 connection (Connection, New).
  6. Select Serial Port. Make sure that the baud rate is set to the same baud rate as the unit.
  7. Click Next.
  8. Name the new connection by typing in a name under "Save Connection As". I recommend putting the baud rate in as part of the name.
  9. Click Finish.
  10. Answer Yes to the question about opening the new connection. This is necessary because the old connection will not work any more because th baud rate of the established connection in PSCSV is not that of the 1133A.