- Apex Generator User Manual
5708009-C 4-63
Apex 1 to 5.5 kW Generator
PROFIBUS/APEX SOFTWARE COMMANDS
The new AE Profibus is command-based. We define a download packet (“outbytes”) 
and an upload packet (“inbytes”) as described in the following sections of this chapter. 
Command lists follow. 
Note: Response times are very fast. So requested information is available in less than 
100 ms. More specifically, a download packet (“outbytes”) has high priority for 
the AE Profibus and is processed immediately. The upload packet has lower 
priority and is updated every 100 ms, with the exceptions of the “output on” 
status bit, which is updated every 20 ms.
Profibus Download Packet
The download packet for the AE Profibus contains four bytes, as the following table 
shows.
In the packet, bytes 1, 2, and 3 comprise the “data field” and contain information 
defined by the command. Note that when the information extends over more than one 
byte, the packet sends the least significant byte (LSB) before the most significant byte 
(MSB); this arrangement is a departure from previous Profibus options we have 
offered. 
Profibus Upload Packet
During every Profibus data exchange, the Apex generator supplies a 14-byte response 
to a download (“outbytes”) packet. The following list shows the response or “upload 
packet.” These bytes are also known as “inbytes.”
Table 4-8. Configuration of Download Bytes (Outbytes)
Byte Description
0 Command
1 Data byte (LSB)
2 Data byte
3 Data byte (MSB)
Table 4-9. Configuration of Profibus Upload Packet (Inbytes)
Byte Description
0 Status flags—first byte
1 Status flags—second 
byte
2 Delivered power low
3 Delivered power high










