Reference Manual

PMAC 2 Software Reference

PMAC I-Variable Specification 159

PMAC can detect one ring communications error per real-time interrupt (I8+1 servo

cycles) even if more than one error has occurred. Valid settings of I1004 are less than

I1001/(I8+1). Regardless of the setting of I1004, if a ring error is detected on every check

during the period, a “ring fault” is declared.

PMAC can detect four types of MACRO communications errors: byte “violation” errors,

packet checksum errors, packet overrun errors, and packet underrun errors.

If I1004 is set to 0 at power-on/reset, the PMAC will automatically set it to 2.

Before I1004 was implemented, a fixed value of 2 ring errors was used.

See Also

I-Variables I8, I995, I1001, I1004

I1005 MACRO Ring Sync Packet Shutdown Count

Range

0 .. 65,535

Units

MACRO sync packets

Default

Remarks

I1005 determines the minimum number of MACRO “sync node” communications packets

(“sync packets”) that must be detected in one ring check period for PMAC to conclude the

the ring is operating properly and permit normal machine operation to continue. This

check is only performed if the I1001 MACRO ring check period parameter is set greater

than 0. In this case, if PMAC detects fewer than I1005 MACRO sync packets in I1001

servo cycles, it will cause the PMAC to “kill” all of its motors.

PMAC can detect one MACRO sync packet per real-time interrupt (I8+1 servo cycles)

even if more than one sync packet has been received in that period. Valid settings of I1005

are less than or equal to I1001/(I8+1). Setting I1005 to a value greater than I1001/(I8+1)

means that PMAC will never receive enough sync packets and will always disable its slave

stations on the ring.

The node number n, 0 to 15, of the sync packet is determined by bits 16 to 19 (the second

hex digit) of I996. This node n must be activated by setting bit n of I996 to 1; otherwise,

PMAC will immediately detect a ring communications error.

If I1005 is set to 0 at power-on/reset, the PMAC will automatically set it to 2.

Before I1005 was implemented, a fixed value of 2 sync packets was used.