BASEstartm Classic DAS
for Allen-Bradley
Data Highwaytm Protocol
Installation and User's Guide
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3.2.4.4 PLC-5

Address syntax and supported device connection management data types for read and write operations vary between the PLC-5/250 and the other PLC-5 family devices.

The following sections describe the use of the read data and write data functions by specific devices, including addressing and data type formats. Addressing and data type formats are necessary for performing the read data and write data functions for the PLC-5 family of devices.

Data Type Formats

Table 3-7 shows which data type formats are supported for reading from and writing to the various file types of the PLC-5 family.

Table 3-7 PLC-5 Data Format General Reference
Device File Type Bit Byte Word Long Float String
Output X   X      
Input X   X      
Status X   X      
Binary X   X      
Timer X   X X    
Counter X   X      
Control X   X      
Integer X   X      
Floating Point         X  
ASCII X X       X
Long Integer X     X    
PID Control X X     X  
Internal Storage X   X      
Shared Data X   X      
Block Transfer Data X   X      
String   X X     X
Adapter Status X X X      
Message X X X      

General Address Formats

The general format for specifying addresses for the PLC-5 family devices is: 


           mFSf:nn/bb  or  mFSf:nn.mne

where:

Specific Address Formats

The following tables describe address specifications and data types for specific PLC-5 family file types. Refer to the general address formats listed above for a description of the conventions used to describe address specifications.

Input File Addresses

Table 3-8 describes address specifications and data types for input file addresses. Input file addresses are identical for all PLC-5 devices and are specified in octal.

Table 3-8 Input File Addresses
Address Format Comment
I :rr Word Input image table word
I :rr/bb Bit Output image table bit

Output File Addresses

Table 3-9 describes address specifications and data types for output file addresses. Output file addresses are identical for all PLC-5 devices and are specified in octal.

Table 3-9 Output File Addresses
Address Format Comment
O :rr Word Output image table word
O :rr/bb Bit Output image table bit

Status File Addresses

Table 3-10 describes address specifications and data types for status file addresses. Status file addresses are identical for all PLC-5 devices, except that a module number must be specified for the PLC-5/250.

Table 3-10 Status File Addresses
Address Format Comment
mS:nn Word Status file word
mS:nn/bb Bit Status file bit

Binary File Addresses

Table 3-11 describes address specifications and data types for binary file addresses. Binary file addresses are identical for all PLC-5 devices, except that a module number must be specified for the PLC-5/250.

Table 3-11 Binary File Addresses
Address Format Comment
mBf:nn Word Binary file word
mBf:nn/bb Bit Binary file bit

Timer File Addresses

Table 3-12 describes address specifications and data types for timer file addresses. Timer file addresses are identical for all PLC-5 devices, except that a module number must be specified for the PLC-5/250. Timers can be read as entire structures or addressed at the sub-element level.

For a PLC-5/250, the accumulator and preset values are longwords and the total structure size is 12. For other PLC-5 family devices, the accumulator and preset values are words.

Table 3-12 Timer File Addresses
Address Format Comment
mTf:nn Array[3]:long PLC-5/250 timer structure
Tf:nn Array[3]:word PLC-5/[12,15,25] timer structure
mTf:PRE Long PLC-5/250 timer preset
Tf:PRE Word PLC-5/[12,15,25] timer preset
mTf:PRE/bb Bit Timer preset bit
mTf:ACC Long PLC-5/250 timer accumulator
Tf:ACC Word PLC-5/[12,15,25] timer accumulator
mTf:ACC/bb Bit Timer accumulator bit
mTf:EN 1 Bit Timer enable bit
mTf:TT 1 Bit Timer timing bit
mTf:DN 1 Bit Timer done bit

1 Control bits should be treated as read only and modified only under PLC program control. Modifying these bits from a computer can give unpredictable results.

Counter File Addresses

Table 3-13 describes address specifications and data types for counter file addresses. Counter file addresses are identical for all PLC-5 devices except, that a module number must be specified for the PLC-5/250. Counters can be read as entire structures or addressed at the sub-element level.

Table 3-13 Counter File Addresses
Address Format Comment
mCf:nn Array[3]:word Entire counter structure
mCf:PRE Word Counter preset
mCf:PRE/bb Bit Counter preset bit
mCf:ACC Word Counter accumulator
mCf:ACC/bb Bit Counter accumulator bit
mCf:CU 1 Bit Counter up enable bit
mCf:CD 1 Bit Counter down enable bit
mCf:DN 1 Bit Counter done bit
mCf:OV 1 Bit Counter overflow bit
mCf:UN 1 Bit Counter underflow bit

1 Control bits should be treated as read only and modified only under PLC program control. Modifying these bits from a computer can give unpredictable results.

Control File Addresses

Table 3-14 describes address specifications and data types for control file addresses. Control file addresses are identical for all PLC-5 devices, except that a module number must be specified for the PLC-5/250.

Table 3-14 Control File Addresses
Address Format Comment
mRf:nn Array[3]:word Entire control structure
mRf:nn.LEN Word Control expression files length
mRf:nn.LEN/bb Bit Length bit
mRf:nn.POS Word Control expression file position
mRf:nn.POS/bb Bit Position bit
mRf:nn.EN 1 Bit Enabled bit
mRf:nn.EU 1 Bit Enabled unloading bit
mRf:nn.DN 1 Bit Done bit
mRf:nn.EM 1 Bit Empty bit
mRf:nn.ER 1 Bit Error bit
mRf:nn.UL 1 Bit Unload bit
mRf:nn.IN 1 Bit Inhibit comparisons bit
mRf:nn.FD 1 Bit Found bit

1 Control bits should be treated as read only and modified only under PLC program control. Modifying these bits from a computer can give unpredictable results.

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