Reference Manual

PMAC 2 Software Reference

PMAC On-Line Command Specification 213

Remarks

This command reserves space in PMAC’s memory or in DPRAM depending upon the setting

of I45 for the data gathering buffer and prepares it for collecting data at the beginning of the

buffer. If a data gathering buffer already exists, its contents are not erased but the Data

Gather Buffer Storage address (Y:$0F20) is reinitialized to the Data Gather Buffer Start

address (X:$0F20) and the LIST GATHER command will no longer function. Data

collection will again start at the beginning of the buffer when the command GATHER is

issued.

If Data Gathering is in progress (an ENDGATHER command has not been issued and the

gather buffer has not been filled up) PMAC will report an error on receipt of this command.

The optional {constant} specifies the number of long words to be reserved for the data

gathering buffer, leaving the remainder of PMAC’s memory available for other buffers such

as motion and PLC programs. If {constant} is not specified, all of PMAC’s unused

buffer memory is reserved for data gathering. Until this buffer is deleted (with the DELETE

GATHER command), no new motion or PLC programs may be entered into PMAC.

Note:

If I45 = 2 or 3 the {size} requested in the DEFINE GATHER

{size} command refers to a DPRAM long word (32-bits). If the

{size} is smaller than required to hold an even multiple of the

requested data, the actual data storage will go beyond the requested

{size} to the next higher multiple of memory words required to

hold the data. For example, if you are gathering one 24-bit value and

one 48-bit value you will need 3 DPRAM long words of memory. If

the {size} you specify is 4000 words (not a multiple of 3), the

actual storage size will be 4002 words (the next higher multiple of 3).

The number of long words of unused buffer memory can be found by issuing the SIZE

command.

Example

DEFINE GATHER

DEFINE GATHER 1000