8
Sample telegrams
8.1
Important communication parameter
1. EXTWD (PNU 1658):
With this parameter, the observation time (watch dog) for the fieldbus-slot
communication can be set. The observation is only active, if a value higher than 0 is assigned to
EXTWD (EXTWD=0, observation switched off) and the output stage is enabled. If the set time ran
off, without the timer being triggered newly, then the warning n04 (response monitoring) is gener-
ated and the drive is stopped. The amplifier remains ready for operation and the output stage
enabled. Before a new driving command (setpoint) is accepted, this warning must be deleted (func-
tion CLRFAULT or INxMODE=14).
2. ADDR (PNU 918):
With this command, the node address of the amplifier is set. When the
address has been changed, all parameters should be saved to the EEPROM and the amplifier
switched off and on again.
Since the modular structure of the PMCtendo DD4 400 as a multi-axis system requires its own
addressing, there is the additional parameter
ADDRFB (PNU 2012)
for this series, with which a field
bus address deviating from the internal device address can be defined. The setting takes place
exactly as with ADDR.
3. AENA (PNU 1606):
With this parameter, the state of the software-enable after switch-on can be
defined. The software-enable allows an external control to enable/disable the output stage. For
amplifiers with analog setpoints (OPMODE=1,3) the software-enable is set automatically after
switch-on and the devices are ready for operation immediately (if hardware-enable is present). For
all others, software-enable will be set to the value of AENA. The variable AENA has also a function
when resetting the amplifier after an error (by digital input 1 or the CLRFAULT command). If an
error can be reset by the software, the software-enable is set to the value of AENA after the error
was cleared. In this way the behavior of the amplifier after a software-reset is similar to the
switch-on reaction.
4. INPT (PNU 1904):
With this parameter a delay for the in-position message can be set. With the
start of a motion task the in-position message is deleted and the monitoring of the position is acti-
vated after expiration of the adjusted time. This function is particularly important for positioning pro-
cedures within the in-position window. In this case it is guaranteed that the in-position message is
suppressed back for a defined time.
User manual PROFIBUS DP PMCtendo DD4
Page 47
8 Sample telegrams