Read Dynamic Variables (Service Code = 0x4B)
Read Dynamic Variables are outlined as follows.
Offset | Field | Value | Definition |
|---|---|---|---|
No Requested Data |
Request Size = 0
Request Failed
The HARTIOM responds with these messages.
Offset | Field | Value | Definition |
|---|---|---|---|
0 | Status | 34 = RUNNING 35 = DEAD | Command status |
1 | Pad | 0 | Pad byte |
Reply Size = 2
Request Succeeded
The HARTIOM responds with these messages.
Offset | Field | Value | Definition |
|---|---|---|---|
0 | Status | 00 = SUCCESS (1 byte) | Command status |
1 | HARTCommandStatus | (1 byte) | HART Device reply Status Byte # 1 |
2 | HARTFieldDeviceStatus | (1 byte) | HART Device reply Status Byte # 2 |
3 | HARTExtDevice Status | (1 byte) | Status Byte returned from Cmd 9 or 0 for 5.x rev HART devices |
4-7 | PV | (Float - 4 bytes) | HART Primary variable |
8-11 | SV | (Float - 4 bytes) | HART Secondary variable |
12-15 | TV | (Float - 4 bytes) | HART Third variable |
16-19 | FV | (Float - 4 bytes) | HART Fourth variable |
20 | PV Units | (1 byte) | Primary variable unit code |
21 | SV Units | (1 byte) | Secondary variable unit code |
22 | TV Units | (1 byte) | Third variable unit code |
23 | FV Units | (1 byte) | Fourth variable unit code |
24 | PV Assignment Code | (1 byte) | Primary variable assignment code |
25 | SV Assignment Code | (1 byte) | Secondary variable assignment code |
26 | TV Assignment Code | (1 byte) | Third variable assignment code |
27 | FV Assignment Code | (1 byte) | Fourth variable assignment code |
28 | PV Status | (1 byte) | 1 byte status from Cmd 9(Rev 6.x) OR if Rev 5.x device: 0xC0 = Connected 0x00 = Not Connected |
29 | SV Status | (1 byte) | 1 byte status from Cmd 9 OR if Rev 5.x device: 0xC0 = Connected and Device provides this value in CMD 3 (that is, does not truncate) 0x00 = Not Connected |
30 | TV Status | (1 byte) | 1 byte status from Cmd 9 OR if Rev 5.x device: 0xC0 = Connected and Device provides this value in CMD 3 (that is,. Does not truncate) 0x00 = Not Connected |
31 | FV Status | (1 byte) | 1 byte status from Cmd 9 OR if Rev 5.x device: 0xC0 = Connected and Device provides this value in CMD 3 (that is, does not truncate) 0x00 = Not Connected |
32-35 | Loop Current | (Float - 4 bytes) | Device reported digital loop current value. (Value from Cmd 3 for Rev 5.x devices or Cmd 2 if Rev 6.x device) |
Reply Size = 36 bytes
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