Precautions - Mitsubishi Electric MELSEC iQ-R Series User Manual

Precautions

When the momentary power failure occurs
The safety communications may stop since the safety communication relay function is discontinued and an error is detected.
The function restarts when the momentary power failure is cleared.
Take any of the following actions.
Action
Take measures for momentary power failure. ( MELSEC iQ-R Module Configuration Manual)
For transmission interval monitoring time, satisfy the following calculation formula.
■Transmission interval monitoring time of the master station (safety station)
TM > (S2cyc  2) + (LS  6) + (PT  2) + 110
■Transmission interval monitoring time of the module set to SIL2 mode Main
TM > (SCmst  2) + (LS  6) + (PT  2) + 110
*1 The meanings of the variables in the equation are as follows.
Variable Meaning
TM Transmission interval monitoring time [ms]
S2cyc Control cycle time of the module set to SIL2 mode Main [ms]
SCmst Safety cycle time of the master station [ms]
LS Link scan time [ms]
PT Allowable momentary power failure time of the power supply module with the remote head module [ms]
When the ring topology is configured
Satisfy the following calculation formula for the transmission interval monitoring time of the module set to SIL2 mode Main.
If the calculation formula is not satisfied, the safety communications stop due to the loopback or clearing it.
• TM≥(SCmst2)+(LS10)+24
*1 The meanings of the variables in the equation are as follows.
Variable Meaning
TM Transmission interval monitoring time [ms]
SCmst Safety cycle time of the master station [ms]
LS Link scan time [ms]
*1
1.9 Safety Communication Relay Function
1
*1
1 FUNCTIONS
75