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Release Notes
ModbusTCP VIM2 4.5.5 Release Notes
By Nobin William
Product: IOD-4111 - Modbus TCP IP Driver for DeltaV VIM2

Product Description

These release notes are for the ModbusTCP VIM firmware v4.5.5. The previous released firmware version is v4.5.5. The flash procedure is documented in the product manual. This version of the firmware is identical to the released firmware v4.5.5, with functionality enhancements and corrected defects as noted below.

Note that when flashing the firmware to v4.5.1 from any version prior to v4.4.1, the VIM will decommission itself. This is due to the device database size change in the VIM.

Who Should Upgrade?

Recommended for all Modbus TCP applications.

Enhancements/Optimizations Implemented

Scan Control Dataset

By default, the VIM performs dataset scans as fast as the network request/response allows. All datasets of each device are continuously scanned in a cycle. All devices are scanned simultaneously.

The port level Message Timeout value, in milliseconds, is configured to discard outstanding data requests to non-responsive devices. However, the maximum time value can be 25500ms. In some cases, this time value is insufficient. Consequently, an extended timeout time is required.

An alternate scan control mechanism is built into the VIM to allow a DeltaV Control Module to trigger dataset scans, on demand, by writing to a special scan control dataset. The scan control dataset is not part of the VIM scan. It affects Input and Output with Readback datasets only. That is, only the reading of field data is controlled by this dataset. If not configured, all VIM scans work by default, as described above. If the dataset is configured, then field reads may be controlled as described below. This dataset may be configured only once for the entire VIM, and may reside under any configured device.

Write requests from DeltaV to the external devices are always handled by exception, and are not a part of the above scan mechanism. Writes have priority over reads. For Output with Readback datasets, only the field read part is controlled by the above mechanism.

Any one dataset out of the 128 available may be configured to be the scan control dataset. Excluding the scan control dataset, all remaining 127 datasets are controlled.

The scan control dataset is configured as follows:

Data Direction Output with Readback
DeltaV Data Type 16-Bit Unsigned Integer
Device Data Type 8
Start Address 0
Number of Values 45
Special Data 1-5 0

The dataset is divided into sections:

  1. Registers 1-8 are scan trigger bits
  2. Registers 9-16 select which datasets are under custom scan control
  3. Register 17-24 contain the extended timeout values
  4. Register 25-32 are dataset scan disable bits
  5. Register 33-38 are device disable bits.
  6. Register 39 is used to enable/disable suppression of all error reporting.
  7. Register 40-45 are device level error ignore/suppress bits.

Registers 1-38 represent existing functionality in firmware versions prior to v4.5.5. Registers 39, and 40-45 are new functionality in this version.


Dataset Scan Trigger Registers

R1 - R8 are used as a bit mask. A bit set to 1 by the DeltaV Control Module triggers a scan of the corresponding dataset. By default, all bits are 0. On normal scan completion or a timeout, the bit is reset to 0. Bit 1 of the register corresponds to Dataset 1, and bit 16 corresponds to Dataset 16. Bits corresponding to unconfigured datasets are ignored.

Datasets in a port are numbered in the order in which they were created, ignoring any devices in the port. Dataset numbers can be viewed from DeltaV Diagnostics.

Simplex VIM Scan Trigger Register Mapping

Register Card/Port Controlled
1 Card 57, Port 1 or Card 61, Port 1
2 Card 57, Port 2 or Card 61, Port 2
3 Card 58, Port 1 or Card 62, Port 1
4 Card 58, Port 2 or Card 62, Port 2
5 Card 59, Port 1 or Card 63, Port 1
6 Card 59, Port 2 or Card 63, Port 2
7 Card 60, Port 1 or Card 64, Port 1
8 Card 60, Port 1 or Card 64, Port 2

Redundant VIM Scan Trigger Register Mapping

Register Card/Port Controlled
1 Card 57/58, Port 1
2 Card 57/58, Port 2
3 Card 59/60, Port 1
4 Card 59/60, Port 2
5 Card 61/62, Port 1
6 Card 61/62, Port 2
7 Card 63/64, Port 1
8 Card 63/64, Port 2

Controlled Dataset Registers

R9 - R16 are a bit mask specifying if a dataset is part of the scan control mechanism. A bit value of 0 implies that the corresponding dataset is not part of scan control (0 by default). Such a dataset will be scanned continuously. If a bit is set to 1, then the dataset will be scanned only if the corresponding bit in registers R1 - R8 is also set. The VIM does not change the values of R9 - R16.

Simplex VIM Scan Control Enabled Register Mapping

Register Card/Port Controlled
9 Card 57, Port 2 or Card 61, Port 1
10 Card 57, Port 2 or Card 61, Port 2
11 Card 58, Port 2 or Card 62, Port 1
12 Card 58, Port 2 or Card 62, Port 2
13 Card 59, Port 2 or Card 63, Port 1
14 Card 59, Port 2 or Card 63, Port 2
15 Card 60, Port 1 or Card 64, Port 1
16 Card 60, Port 1 or Card 64, Port 2

Redundant VIM Scan Control Enabled Register Mapping

Register Card/Port Controlled
1 Card 57/58, Port 1
2 Card 57/58, Port 2
3 Card 59/60, Port 1
4 Card 59/60, Port 2
5 Card 61/62, Port 1
6 Card 61/62, Port 2
7 Card 63/64, Port 1
8 Card 63/64, Port 2

Extended Timeout

For R17 - R24, a non-zero number specifies the message timeout value to be used, instead of the normal port level timeout. The time units are 5 seconds per count. If the register contains a 2, then all datasets under the corresponding port will timeout after 10 seconds. The maximum value can be 65535, which amounts to a timeout of 91 hours.

Extended Port timeout (in seconds) = 5 * register value

Note: This timeout is independent of the manual dataset scan control. If a dataset has a zero in R9 - R16 and a non-zero value in R17 - R24, the extended timeout will still override the port level timeout setting.

Simplex VIM Extended Message Timeout Register Mapping

Register Card/Port Controlled
17 Card 57, Port 2 or Card 61, Port 1
18 Card 57, Port 2 or Card 61, Port 2
19 Card 58, Port 2 or Card 62, Port 1
20 Card 58, Port 2 or Card 62, Port 2
21 Card 59, Port 2 or Card 63, Port 1
22 Card 59, Port 2 or Card 63, Port 2
23 Card 60, Port 1 or Card 64, Port 1
24 Card 60, Port 1 or Card 64, Port 2

Redundant VIM Extended Message Timeout Register Mapping

Register Card/Port Controlled
17 Card 57/58, Port 1
18 Card 57/58, Port 2
19 Card 59/60, Port 1
20 Card 59/60, Port 2
21 Card 61/62, Port 1
22 Card 61/62, Port 2
23 Card 63/64, Port 1
24 Card 63/64, Port 1

Dataset Scan Disable

R25 - R32 are a bit mask specifying if the scan of a dataset has been completely disabled. A bit value of 0 implies that the corresponding dataset is part of the scan, either controller or continuous. Note that the values are 0 by default. If a bit is set to 1, then the dataset will not be scanned. Instead, an error will be reported to DeltaV Diagnostics indicating the dataset state (“Disabled Dataset via Scan Control”). In this way the datasets of one or more devices may be removed from the scan if the devices are down for maintenance. Scan of all other devices will continue to function normally. The VIM does not change the value of registers R25-R32.

Simplex VIM Extended Message Timeout Register Mapping

Register Card/Port Controlled
25 Card 57, Port 2 or Card 61, Port 1
26 Card 57, Port 2 or Card 61, Port 2
27 Card 58, Port 2 or Card 62, Port 1
28 Card 58, Port 2 or Card 62, Port 2
29 Card 59, Port 2 or Card 63, Port 1
30 Card 59, Port 2 or Card 63, Port 2
31 Card 60, Port 1 or Card 64, Port 1
32 Card 60, Port 1 or Card 64, Port 2

Redundant VIM Extended Message Timeout Register Mapping

Register Card/Port Controlled
25 Card 57/58, Port 1
26 Card 57/58, Port 2
27 Card 59/60, Port 1
28 Card 59/60, Port 2
29 Card 61/62, Port 1
30 Card 61/62, Port 2
31 Card 63/64, Port 1
32 Card 63/64, Port 1

Device Disable

The device disable registers comprise a mask specifying if a device is enabled or disabled. Table 10 list the devices represented with each register. A bit value of 0 implies that the corresponding device is enabled (default value), and a bit value of 1 represents a disabled device. Bit 1 of the R33 corresponds to Device 1, and bit 16 corresponds to Device 16. Similarly, bit 1 of R34 corresponds to Device 17, and bit 16 corresponds to Device 32. The bit number is the device creation order in the VimNet Explorer. It is called the Network Index in the VimNet Explorer, VIM level display. Specifically, the first device created is controlled by R33 bit 1. The second device created is controlled by R33 bit 2, etc.

The VIM will attempt to connect to all enabled devices and not connect to disabled devices. Setting a bit while the VIM is online will cause the device to be disconnected. If a bit is set to 1, all datasets in the device will report an error to DeltaV Diagnostics indicating the device state (“Disabled Device”).

Device Disable Registers

Register Controlled Devices
33 Devices 1-16
34 Devices 17-32
35 Devices 33-48
36 Devices 49-64
37 Devices 65-80
38 Devices 81-96

Enable/Disable Suppression of Error Reporting

Datasets or Devices disabled via Scan Control will by default report an error message to DeltaV. These error messages are visible in DeltaV Diagnostics. The purpose of these errors is to clearly mark the datasets/devices as disabled and unavailable. Users can, however, suppress the error reporting. When suppressed, the disabled datasets and all datasets associated with disabled devices will not be marked as being in error. There will be no indication in DeltaV that the datasets/devices are disabled. Furthermore, the registers in the disabled datasets will contain stale data with good status. If error reporting is suppressed, it is the users responsibility to ensure stale data is not inadvertently used in their live process handling.

R39, Bit 16 is the flag used to enable/disable error reporting suppression. This flag, when set, enables the actions expected by setting flags in R40 and R41 (see below).

Bit 1-15 Reserved
Bit 16 Bit 0 - Error Reporting Enabled (not suppressed)
Bit 1 - Error Reporting Disabled (suppressed)

Ignore/Suppress all Device Errors

The device error ignore registers comprise a mask specifying if the VIM will report any errors for the given device. Table 11 lists the devices represented with each register. A bit value of 0 implies that the corresponding device will report all errors (default value), and a bit value of 1 represents a device for which all errors will be ignored. In the default reporting state, the device is subject to error reporting as dictated by dataset enable/disable, and device enable/disable as described above.

Bit 1 of R40 corresponds to Device 1, and bit 16 corresponds to Device 16. Similarly, bit 1 of R41 corresponds to Device 17, and bit 16 corresponds to Device 32. The bit number is the device creation order in the VimNet Explorer. It is called the Network Index in the VimNet Explorer, VIM level display. Specifically, the first device created is controlled by R40 bit 1. The second device created is controlled by R40 bit 2, etc.

If an error ignore/suppression bit is set for a device, the VIM is apply that only if R39, bit 16 is also set. All device errors will be ignored. Ignored errors include field device connectivity, dataset misconfiguration, invalid dataset responses, etc. The VIM will always report a good status for the device. It will be the users responsibility to validate data veracity, e.g., by using a watchdog.

Suppression of all Device Errors

Register Controlled Devices
40 Devices 1-16
41 Devices 17-32
42 Devices 33-48
43 Devices 49-64
44 Devices 65-80
45 Devices 81-96

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