Detailed Description   
2.1 NC/PLC interface signals 
  Various NC/PLC Interface Signals and Functions (A2) 
2-22  Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0 
DB31, ... DBX94.3 (|Md| < Mdx)  
This signal indicates that the current torque |M
d
| is less than the assigned threshold torque 
M
dx
: 
MD1428 $MD_TORQUE_THRESHOLD_X 
The threshold torque is entered as a percentage of the current speeddependent torque 
limitation. 
DB31, ... DBX94.4 (|nact| < nmin)  
This signal indicates that the actual speed value |n
actual
| is less than the set minimum speed 
n
min
: 
MD1418 $MD_SPEED_THRESHOLD_MIN 
DB31, ... DBX94.5 (|nact| < nix)  
This signal indicates that the actual speed value |n
actual
| is less than the set threshold speed 
x
: 
MD1417 $MD_SPEED_THRESHOLD_X 
DB31, ... DBX94.6 (nact = nsetp)  
It is signaled to the PLC that the actual speed value n
actual
 has reached the new setpoint, 
taking into account the tolerance band set in the drive machine datum: 
MD1426 $MD_SPEED_DES_EQ_ACT_TOL, 
and is still within the tolerance band.  
DB31, ... DBX94.7 (variable signaling function) (not 810D)  
Using the variable signaling function, it is possible to monitor digitally for any axis any 
variable from SIMODRIVE 611 to check if it violates a certain threshold and to signal as an 
interface signal to the PLC.  
The variable to be monitored is specified with 611D machine data. 
DB31, ... DBX95.0 (DC link voltage < warning level)  
A message is sent from the drive to the PLC that the DC link voltage U
DClink
 is smaller than 
the DC link undervoltage threshold: 
MD1604 $MD_LINK_VOLTAGE_WARN_LIMIT 
DB31, ... DBX95.7 (i
2
t monitoring) (not 810D)  
The variable signaling function can be used to protect the power section of the SIMODRIVE 
611 universal and SIMODRIVE 611 digital drives against continuous overload. The PLC is 
signaled for each axis indicating whether the i
2
t monitoring has been initiated. 
The variable to be monitored is specified with 611D machine data.