Spectrum Controls 1769sc-HART Modules User Manual
Page 74
Compact IO™ Isolated HART Analog Output Module
User’s Manual 0300217-03 Rev. A
7-8
Table 7-5 (HART Packet 4)
Tag Name
Data Type
Style Description
If4ih0Packet4
Packet4[4,1] NA
Two dimensional array containing
packet 4 data for all 4 channels.
If4ih0Packet4[X,0].HartChannelID
INT
BIN
Bits 0 to 3: Channel number (0 – 3).
Bit 4: Searching/Initializing HART device
Bit 5: HART communication failure or
device not found
Bit 6: Pass-through message pending
(ready)
Bit 7: Unused (0)
Bits 8 to 10: Packet ID
Bit 11 through 15: Unused
If4ih0Packet4[X,0].Date
SINT[3]
DEC Stored date in the field device
If4ih0Packet4[X,0].FinalAssemblyNumber
SINT[3]
DEC The final assembly number is used for
identifying the materials and electronics
that comprise the field device.
If4ih0Packet4[X,0].ExtendedStatus
SINT[24]
DEC The extended status returned by HART
command 48
If4ih0Packet4[X,0].Pad
SINT[3]
DEC Pad 32 bit alignment
1
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 command, 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.