Apex Digital 5708009-C manual PROFIBUS/APEX Software Commands, Byte Description

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.

Table 4-8.Configuration of Download Bytes (Outbytes)

Byte Description

0Command

1Data byte (LSB)

2Data byte

3Data byte (MSB)

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 4-9.Configuration of Profibus Upload Packet (Inbytes)

Byte Description

0Status flags—first byte

1Status flags—second byte

2Delivered power low

3Delivered power high

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