Delta Tau Geo MACRO, User Manual And Reference Manual

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Geo MACRO Drive User Manual
136 Geo Macro Drive MI-Variable Reference
The Station can detect four types of communications errors: byte “violation” errors, packet checksum
errors, packet overrun errors, and packet under run errors. If MI9 errors have occurred in the MI8 check
period, and at least half of these errors are byte “violation” errors, the Station will conclude that there is a
ring break immediately upstream of it (if there are no ring input communications to the Station, there will
be continual byte violation errors). In this case, not only will it set its servo command output values to
zero, set its amplifier enable outputs to the “disable” state, and force all of its digital outputs to their
“shutdown” state as defined by MS{node},MI13, but it will also turn itself into a master so it can report to
other devices downstream on the ring.
If MI9 is set to 0 at power-on/reset, the Geo MACRO Station will automatically set it to 4.
MS{node},MI10 Geo MACRO Sync Packet Shutdown Count
Range: 0 – 65,535
Units: none
Default: 8
MI10 determines the number of Geo MACRO Ring “sync packets” that must be received during a check
period for the Station to consider the ring to be working properly. If the Station detects fewer than MI10
sync packets in MI8 phase (Geo MACRO Ring) cycles, it will shut down on a Geo MACRO
communications fault, setting its servo command output values to zero, setting its amplifier enable
outputs to the “disable” state, and forcing all of its digital outputs to their “shutdown” state as defined by
MS{node},MI13.
The node number (0-15) of the sync packet is determined by bits 16-19 of Station variable MI996. On the
Geo MACRO Station, this is always node 15 ($F), because this node is always active for Geo MACRO
Type 1 auxiliary communications.
The Station checks each phase cycle to see if a sync packet has been received or not. Setting MI10 to 0
means the Station will never shut down for lack of sync packets. Setting MI10 greater than MI8 means
that the Station will always shut down for lack of sync packets.
If MI10 is set to 0 at power-on/reset, the Geo MACRO Station will automatically set it to 4.
MS{node},MI11 Station Order Number
Range: 0 – 254
Units: none
Default: 0
MI11 contains the “station-order” number of the Geo MACRO Station on the ring. This permits it to
respond to auxiliary MACROSTASCIIn commands from a Turbo PMAC ring controller, regardless of
the Geo MACRO Station’s binding to a MACRO Master.
The station ordering scheme permits the ring controller to isolate each master or slave station on the ring
in sequence and communicate with it, without knowing in advance how the ring is configured or whether
there are any conflicts in the regular addressing scheme. This is very useful for the initial setup and
debugging of the ring configuration.
Normally, station order numbers of devices on the ring are assigned in numerical order, with the station
downstream of the ring controller getting station-order number 1. This does not have to be the case,
however.
“Unordered” stations have the station-order number 0. When the ring controller executes a