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Old October 14th, 2009   #2
sblair
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Tim,

The PDL is always the number of bytes, regardless of the data type. PDL Size is used to tell the controller what to expect the PDL to be for a GET_COMMAND_RESPONSE or SET_COMMAND_RESPONSE message.

There are a number of flaws you'll find documented on here with the Parameter Description message but it still has some basic uses. Strictly speaking by Table A-15, you can have arrays of values, but most commonly it will be an array size of 1. i.e. a single data value.

In the case of a single DWORD value, the PDL would be 0x04 with leading 0's to pad out the field.

A PDL of 0x02 and an actual value of 0x0006 would indicate a 16-bit value. If the PDL is 0x04 then the actual value would be: 0x00000006.
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