t represents the type of data, if there are any special conventions. See the following section “Special Naming Conventions” for details.

-b represents the reading of individual bits. Not present if reading whole registers or an array of registers. See the following section “Individual Bits in Registers” for details.

R <f> <[X]nnnn> [t] [A] [lll] [-b]

A indicates that the data is an Array. See the following section “Register Array Format” for details.

lllprovides the length of the array or ASCII string in bytes, This field is present only if the address represents an array or an ASCII string. Leading zeros are not required for this field.

Standard Data Organization

Data is organized according to data type, numeric range, tag type, and access type.

Data Types

There are four data types typically used by the GE devices. These four data types are the possible values for ‘f’ in the address. (Each data type is organized in a separate table for each device in this manual):

1.Dynamic Value

2.Setpoint

3.Command Coil

4.Fixed Value

Each data type is assigned a range of register numbers, tag type, and access as shown below:

Data Organization

Data

Use

Register

Register

DDE

Type of

Type

 

Range

Range

Tag

Access

 

 

(hex)

(decimal)

Type

 

Command

1. Commands a device to take

R0X0000 –

R00000 –

Discrete

Read and

Coil

action.

R0XFFFF

R09999

 

Write

 

2. Reads the status of an

 

 

 

 

 

action or discrete input.

 

 

 

 

Dynamic

Read frequently, such as

R3X0000 –

R30000 –

Analog

Read Only

Value

metering values which change

R3XFFFF

R39999

 

 

 

constantly

 

 

 

 

Fixed

Read only once at power-up.

R4X0000 –

R40000 –

Analog

Read Only

Value

Info such as Product ID and

R4XFFFF

R49999

 

 

 

configuration options

 

 

 

 

Setpoint

Read infrequently

R4X0000 –

R40000 –

Analog

Read Only

 

 

R4XFFFF

R49999

 

 

DDE Server User’s Guide

Appendix A – Register Addressing Conventions 81

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Image 84
Black Box GEH-6510 manual Standard Data Organization, Data Types