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TTM Network Administration Documentation

Configuring the PGM Buffer Size

About the PGM Buffer

TTM Daemons use the PGM buffer to store message data until the TTM Daemon processes it. By increasing the PGM buffer size, the computer can buffer more PGM data during periods with heavy bursts, which can prevent data from being dropped (NAKs).


Increasing the size of this buffer can reduce NAKs, but also introduces additional delays for receiving messages. Consequently, you should consider this option only when the number of NAKs becomes unacceptable.


You should change this value only in consultation with TT Support personnel.

PGM Buffer Size Parameter

The following <General> section parameter sets the PGM buffer size.

PGM Buffer Size Parameter

Sets the size, in bytes, of the PGM buffer.

You must use a whole number to set a value for PGMBufferSize. Valid values range from 1024 - 67108864 (1KB-64MB)

TTM 7.1.17 and higher contains an enhancement that allows the user to increase the PGM buffer up to 1073741824 (1GB).

How to Configure the PGM Buffer Size

To configure the PGM buffer size:

  1. Using Notepad, open the ttmd.cfg file located in <root drive>:ttconfig.
  2. On the Edit menu, click Find.
  3. In the Find what box, type PGMBufferSize.
  4. Click Find Next.
  5. To close the Find dialog box, click Cancel.
  6. If the search does not find the string, in the <General> section, type PGMBufferSize= on a new line.
  7. Set the value to the desired size.
  8. Save and then close ttmd.cfg.
  9. Stop and restart TTM.