ROC GC Write Override Tab

GC Write Override Tab

The GC Write tab allows users to configure which TLPs are written to upon gas chromatograph write events.

Configuring GC Write override is optional. If you do not configure GC Write overrides here, the ROC protocol will default to the following TLPs:

If you do link a Gas Chromatograph object for a specific meter and you wish to override the default TLP that is written to for a specific component, you must be explicit which TLP you would like to write to. In the example below, for the meter in question, when the user or system sends a USERDEFINEDDOUBLE1 value, that value will be written to the soft point 98.3:4. Since all the other component entries in that Gas Chromatograph object example are empty, they will default to the TLP as defined in the table above.

Supported Op_Codes

The following specific Host-to-RTU operational codes are supported:

Physical I/O Addressing

For I/O points such as discrete inputs and outputs, and analog inputs and outputs, a specific point is requested by specifying its “TPL” or Point Type, Parameter, and Physical Location in the I/O module rack.

NOTE: This is more commonly known as “TLP” in the ROC Protocol, but the format used in ACM is “TPL.”

Point Type and Parameter

The Point Type and Parameter can be represented by text, number, or a combination of the two. For example, if you wanted to request the “Filtered EU value (Parameter 14)” of the “ROC Analog Input (Point Type 3),” you could enter the “ROC Analog Input (Point type 3)” as the text “AI” or as the number “3,” and the “Filtered EU value (Parameter 14)” as the text “FILTERED_EU” or as the number “14.” Item names are not case sensitive.

Examples:

NOTE: Most of the point types and parameters can be found in the “Protocol Items” section of this manual, and all of the point types and parameters can be found in the ROC and ROC Plus Protocol Specifications Manuals as provided by the manufacturer.

Physical location numbers in the ROC unit begin at one (1), whereas physical location numbers for the ROC protocol in ACM are zero-based and begin at zero (0). The Physical location can be found when configuring the RTU in ROCLINK, and can be related to the meter run number or can be displayed in ROCLINK as “Point Number”. Point number will be displayed in ROCLINK in one of two ways, but when used with ACM, it will need to be converted into its decimal equivalent. The screenshots and tables below indicate where to find the Point Number and the definition of the conversions.

Point Number in ROCLINK
The Point number can be found on this display in ROCLINK:

Converting Point Number to decimal equivalent

Use the following syntax to address I/O points by their physical location:
<T.P:L> or <IO Point Type>.<Parameter>:< Physical Location >.

• Examples:
  Use AI.FILTERED_EU:0, 3.14:0, AI.14:0, or 3.FILTERED_EU:0 to read the Filtered EU parameter from an AI module located in point number A1.

• Use DI.STATUS:4, 1.2:4 to read the Status parameter from a DI module located in point number A5.

ROC Plus Protocol for ROC800 Series

In this Series the Logical Compatibility Mode (found under ROC -> Information in ROCLink - see screen shot below) can be configured to be 16-Points Per Module or 8-Points Per Module. This will determine which conversion chart will be used.

Find the Point Number in ROCLINK
The Point number can be found on this display in ROCLINK:

If the Logical Compatibility Mode is set to 8-Points Per Module, use the following conversion chart:

Converting Point Number to Decimal Equivalent: 8-Point Logical

If the Logical Compatibility Mode is set to 16-Points Per Module, use the conversion chart below. Note that logical numbers beyond 239 are not available to be polled.

Converting Point Number to Decimal Equivalent: 16-Point Logical

Use the following syntax to address I/O points by their physical location:
<T.P:L> or <IO Point Type>.<Parameter>:< Physical Location >.

Examples:

• Use AI.FILTER:80, 103.5:80, AI.5:80, or 103.FILTER:80 to read the Filter parameter from an AI module located in point number 5-1.

• Use DI.STATUS:119, 101.3:119, DI.3:119, or 101.STATUS:119 to read the Status parameter from a DI module located in point number 7-8.

Physical Locations of modules for ROC 800 series
The following picture shows how modules locations are numbered in the ROC809 (ROC Plus Protocol). This is another way that you can find the physical location numbers.

ROC 800 Module Offsets

Logical I/O Addressing

I/O Modules can be addressed by their logical order (zero based) beginning with ROC Version 5.5.3.0. Use the following syntax to address I/O points logically:
<IO Point Type>.<Parameter>:L<zero based logical offset>.

Examples:

• Use Di.Status:L2 to read the status parameter of the third DI in the ROC.

• Use Ai.Filter:L6 to read the filter parameter from the seventh AI in the ROC.

NOTE: Use the RE_INITIALIZE_IO item to control the reading of the IO Modules Configuration. See the definition of this item in the items section of this document for more details.

Bit Access of Data

Bits of any Integer type items can be accessed individually. To access a single bit, use the normal DDE item name for the item and append a slash (/) followed by the bit number. Bit numbers start at zero (0) for the first bit. For example, to access the Low Low Alarm (bit 1) of Discrete Input point number 3, use the item name DI.ALARM_CODE:2/1. The slash and bit number must follow the item name and number and precede any optional specifications.