ElmoMC SimplIQ Command Reference - Manual (Page 154)

TM - System Time
Purpose:
Reads and writes the system time, in microseconds. SimplIQ drives have a 32-bit
microsecond counter. In the absence of CAN SYNC and TSTAMP signals, the
microsecond counter runs freely, completing a cycle approximately once per 71.5
minutes. The CAN SYNC and TSTAMP sequence synchronize this counter to the
microsecond counter of the network master (refer to the
SimplIQ CAN Implementation
Manual).
The BT command uses the TM variable to coordinate the start of motion. The tdif( )
function uses TM to calculate time differences.
Notes:
ƒ When CAN communication is used, setting or updating the system counter by the
user may upset the synchronization with the CAN network master.
ƒ The tick system function also reads the system time of the SimplIQ , drive, but its
value differs from the TM command value.
Attributes: Type: Command/Parameter, Integer
Source: Program, RS-232, CANopen
Restrictions: None
Default value: None,
Volatile
Unit modes: All
Activation: Immediate
Examples:
QP[1023]=TM
Read TM into a software variable (here, QP[1023] is used as general
storage, not as motion reference).
tdif( QP[1023] ) Return the time elapsed since TM was sampled into QP[1023].
TM=0 Reset system time to zero.
The time returned by this command may jump due to a CAN master update (refer
to the Elmo CANopen Implementation Guide.
See also:
BT
Reference chapter in the SimplIQ Software Manual:
Chapter 4, ”The Interpreter Language” (tdif function)
SimplIQ Command Reference Manual Alphabetical Listing
MAN-SIMCR (Ver. 4.5)
3-141