- Apex Generator User Manual

5708009-C 4-61
Apex 1 to 5.5 kW Generator
Placing a switch in the “up” position (toward the number) is the same as indicating
“1” binary. The following example demonstrates switch settings for an address of 12:
0000 1100 = 0x0Ch = 12.
Note: You cannot change the unit’s address from the Profibus master.
Profibus Termination
Please ensure that you follow proper termination procedures if your Apex is the last
slave on the Profibus cable. The termination resistors should be on the connector
housing of the Profibus cable (not included).
Profibus Baud Rate
The auto-baud feature of AE’s certified Profibus interface adjusts automatically to the
rate of the Profibus master system. Baud rates are available in discrete steps from
9600 bits (9.6 kbits) to 12 Mbits. The auto-baud feature operates much like a modem
or FAX machine in that, at startup, there is a small delay while the interface
“traverses” the different baud rates and then locks in. Please ensure that your Profibus
master allows for this delay.
Profibus Master Reset Command
Send the master reset command, Command 119, when the Apex supply has
experienced a non-recoverable (“explicit clear”) fault (that is, a configuration fault or
a Profibus error fault). We recommend sending this command upon the startup of
Profibus communications so that any existing fault indications will be cleared.
Profibus Watch Dog Timer
As a safety feature, the Profibus maintains a watch dog timer that shuts off the Apex
supply’s output if the Profibus master stops communicating. The watch dog timer
maintains a value for time (between 10 ms and 10 minutes) that the Apex supply waits
between commands from the master. The timer counts down this time in 10 ms
increments.
If your Profibus system does not calculate the watch dog timer value for you or if you
want to modify the existing watch dog timer value, then you may enter a timer value
by using the Profibus Set_Prm function call (see DIN 19245 Profibus Standard Part
III). To get the actual wait time value, the Apex microprocessor uses the numbers you
enter to octet 2 and 3 of the Set_Prm, multiplies them together, and then multiplies the
result by 10 ms. Therefore, when using the Set_Prm function call, calculate the
numbers for octet 2 and 3 accordingly. Remember, the values for octet 2 and 3 must
not be equal to each other or be zero.
Note: You can disable the watch dog timer through the Profibus master.