Datasheet

LM628, LM629
SNVS781C JUNE 1999REVISED MARCH 2013
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LPES COMMAND: LOAD POSITION ERROR FOR STOPPING
Command Code:1A Hex
Data Bytes:Two
Data Range:0000 to 7FFF Hex
Executable During Motion:Yes
Instruction LPES is essentially the same as command LPEI above, but adds the feature of turning off the motor
upon detecting excessive position error. The motor drive is not actually switched off, it is set to half-scale, the
offset-binary code for zero. As with command LPEI, bit 5 of the status byte is also set to logic high. The first byte
of threshold data written with command LPES is the more significant. The user can have the LM628 interrupt the
host to signify that an excessive position error has occurred. See the descriptions for commands MSKI and RSTI.
SBPA COMMAND:
Command Code:20 Hex
Data Bytes:Four
Data Range:C0000000 to 3FFFFFFF Hex
Executable During Motion:Yes
This command enables the user to set a breakpoint in terms of absolute position. Bit 6 of the status byte is set to
logic high when the breakpoint position is reached. This condition is useful for signaling trajectory and/or filter
parameter updates. The user can also arrange to have the LM628 interrupt the host to signify that a breakpoint
position has been reached. See the descriptions for commands MSKI and RSTI.
SBPR COMMAND:
Command Code:21 Hex
Data Bytes:Four
Data Range:See Text
Executable During Motion:Yes
This command enables the user to set a breakpoint in terms of relative position. As with command SBPA, bit 6 of
the status byte is set to logic high when the breakpoint position (relative to the current commanded target
position) is reached. The relative breakpoint input value must be such that when this value is added to the target
position the result remains within the absolute position range of the system (C0000000 to 3FFFFFFF hex). This
condition is useful for signaling trajectory and/or filter parameter updates. The user can also arrange to have the
LM628 interrupt the host to signify that a breakpoint position has been reached. See the descriptions for
commands MSKI and RSTI.
MSKI COMMAND: MASK INTERRUPTS
Command Code:1C Hex
Data Bytes:Two
Data Range:See Text
Executable During Motion:Yes
The MSKI command lets the user determine which potential interrupt condition(s) will interrupt the host. Bits 1
through 6 of the status byte are indicators of the six conditions which are candidates for host interrupt(s). When
interrupted, the host then reads the status byte to learn which condition(s) occurred. Note that the MSKI
command is immediately followed by two data bytes. Bits 1 through 6 of the second (less significant) byte written
determine the masked/unmasked status of each potential interrupt. Any zero(s) in this 6-bit field will mask the
corresponding interrupt(s); any one(s) enable the interrupt(s). Other bits comprising the two bytes have no effect.
The mask controls only the host interrupt process; reading the status byte will still reflect the actual conditions
independent of the mask byte. See Table 3.
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