Delta Tau PMAC2A-PC/104 manual Software Setup, Communications, Pmac I-Variables

PMAC2A PC104 Hardware Reference Manual

SOFTWARE SETUP

Note:

The PMAC2A PC/104 requires the use of V1.17 or newer firmware. There are few differences between the previous V1.16H firmware and the V1.17 firmware other than the addition of internal support for the Flex CPU design.

Communications

Delta Tau provides software tools that allow communicating with of the PMAC2A PC/104 board by either its standard RS-232 port or the optional USB or Ethernet ports. PEWIN is the most important in the series of software accessories, and it allows configuring and programming the PMAC for any particular application.

PMAC I-Variables

PMAC has a large set of Initialization parameters (I-variables) that determine the "personality" of the card for a specific application. Many of these are used to configure a motor properly. Once set up, these variables may be stored in non-volatile EAROM memory (using the SAVE command) so the card is always configured properly (PMAC loads the EAROM I-variable values into RAM on power-up).

The programming features and configuration variables for the PMAC2A PC/104 are described fully in the PMAC2 User and Software manuals.

Operational Frequency and Baud Rate Setup

Note:

Older PMAC boards required a start-up PLC for setting the operational frequency at 80 MHz. That method is not compatible with the PMAC2A PC/104 board and will shutdown the board when used.

The operational frequency of the CPU can be set in software by the variable I46. If this variable is set to 0, PMAC firmware looks at the jumpers E2 and E4 to set the operational frequency for 40, 60, and 80 MHz operation. If I46 is set to a value greater than 0, the operational frequency is set to 10MHz * (I46 + 1), regardless of the jumper setting. If the desired operational frequency is higher than the maximum rated frequency for that CPU, the operational frequency will be reduced to the rated maximum. It is always possible to operate the Flex CPU board at a frequency below its rated maximum. I46 is used only at power-up/reset, so to change the operational frequency, set a new value of I46, issue a SAVE command to store this value in non-volatile flash memory, then issue a $$$ command to reset the controller.

To determine the frequency at which the CPU is actually operating, issue the TYPE command to the PMAC. The PMAC will respond with five data items, the last of which is CLK Xn, where n is the multiplication factor from the 20 MHz crystal frequency (not 10 MHz). n should be equivalent to (I46+1)/2 if I46 is not requesting a frequency greater than the maximum rated for that CPU board. n will be 2 for 40 MHz operation, 4 for 80 MHz operation, and 8 for 160 MHz operation.

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