User Manual

Compact IO™ Isolated HART Analog Output Module

User’s Manual 03 00217-03 Rev. A

7-8

Table 7-5 (HART Packet 4)

Tag Name Data Type

Style

Description

If4i h0 P ack et4 P ack et 4 [ 4,1] NA Two di m ensional array c ontaini ng

packet 4 data for all 4 channel s .

If4ih0Packet4[X,0].HartChannelID INT BI N

Bits 0 to 3: Channel number (0 – 3 ).

Bit 4 : S earching/Initi a lizing HART devi ce

Bit 5: HART c ommunica tion failure or

device not found

Bit 6: P a ss- t hrough message pending

(ready)

Bit 7: Unused (0)

Bits 8 to 10: Packet ID

Bit 11 thr ough 15: Unused

If4ih0Packet4[X,0].Date SI N T[3] DEC

Stor e d da te in the field device

If4ih0Packet4[X,0].FinalAssemblyNumber SINT[3] DEC

The final assembly number is used for

identi fyi ng the material s and electroni cs

that compr ise the fiel d device.

If4ih0Packet4[X,0].ExtendedStatus SINT[24] DEC

The extended status retur ned by H ART

command 48

If4ih0Packet4[X,0].Pad SINT[3] DEC

Pad 32 bit alignment

X represents the module channel number (0 to 3)

Note: Not all of the HART data that is returned by the process outlined in Figure 7-4

(Auto Acquisition Flow) gets passed to the packets. In order to access the data that is

not passed to the packets, you must execute the appropriate HART message using the

pass-through co mmand, which will be discussed later in this chapter.

The ladder determines which packet to copy the data to, by monitoring the state of bits 0,

1, 2 and 8, 9, 10, found in the first two bytes of the OF4IH0Input.HartData tag. Bits 0, 1,

2 determine the current channel being scanned and bits 8, 9, and 10 determine the packet

number. The ladder example, shown in Figure 7-4, performs this operation.