Allen-Bradley DF1 Driver
Device Setup
Device Properties
Operating Mode
Supported Devices
Micrologix Series*
SLC500 Series*
PLC-5 Series (excluding the PLC-5/250 and PLC-5/VME series)
RSLogix5000 Controllers with DF1 Port
*Radio Modem link protocol requires the following firmware upgrades:
SLC 5/03, SLC 5/04 and SLC 5/05: Series C FRN6
MicroLogix 1200: Series C FRN7
MicroLogix 1500: Series C FRN8
DH-485 and DH+ Support
An Allen Bradley KF3 or compatible device is needed to connect the driver to the DH-485 network. There are four options for communicating to a device on DH+: l l
Allen Bradley KF2 or compatible device.
1784-U2DHP USB converter. This converter appears as a new serial port to the system.
l
DataLink DL Interface Cards (PCI/ISA/PC104). These cards add virtual serial ports for seamless configuration.
l
DataLink DL4500 Ethernet-to-DH+ Converter. Configure the device for Ethernet Encapsulation. NIC is required.
See Also:
Device Properties - General
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Allen-Bradley DF1 Driver
Identification
Name: User-defined identity of this device.
Description: User-defined information about this device.
Channel Assignment: User-defined name of the channel to which this device currently belongs.
Driver: Selected protocol driver for this device.
Model: The specific version of the device.
ID Format: Select how the device identity is formatted. Options include Decimal, Octal, and Hex.
ID: The device ID is the Allen-Bradley DF1 network address of the PLC. For PLCs on a DH-485 or DH+ network, the range is 1-63. Otherwise, the range is 0-255.
Operating Mode
Data Collection: This property controls the device's active state. Although device communications are enabled by default, this property can be used to disable a physical device. Communications are not attempted when a device is disabled. From a client standpoint, the data is marked as invalid and write operations are not accepted. This property can be changed at any time through this property or the device system tags.
Simulated: This option places the device into Simulation Mode. In this mode, the driver does not attempt to communicate with the physical device, but the server continues to return valid OPC data. Simulated stops physical communications with the device, but allows OPC data to be returned to the OPC client as valid data.
While in Simulation Mode, the server treats all device data as reflective: whatever is written to the simulated device is read back and each OPC item is treated individually. The item's memory map is based on the group
Update Rate. The data is not saved if the server removes the item (such as when the server is reinitialized).
The default is No.
Notes:
1. This System tag (_Simulated) is read only and cannot be written to for runtime protection. The System tag allows this property to be monitored from the client.
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Allen-Bradley DF1 Driver
2. In Simulation mode, the item's memory map is based on client update rate(s) (Group Update Rate for
OPC clients or Scan Rate for native and DDE interfaces). This means that two clients that reference the same item with different update rates return different data.
Simulation Mode is for test and simulation purposes only. It should never be used in a production environment.
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Device Properties - Scan Mode
The Scan Mode specifies the subscribed-client requested scan rate for tags that require device communications. Synchronous and asynchronous device reads and writes are processed as soon as possible; unaffected by the Scan Mode properties.
Scan Mode: specifies how tags in the device are scanned for updates sent to subscribed clients.
Descriptions of the options are: l l
Respect Client-Specified Scan Rate: This mode uses the scan rate requested by the client.
Request Data No Faster than Scan Rate: This mode specifies the maximum scan rate to be used.
The valid range is 10 to 99999990 milliseconds. The default is 1000 milliseconds.
Note: When the server has an active client and items for the device and the scan rate value is increased, the changes take effect immediately. When the scan rate value is decreased, the changes do not take effect until all client applications have been disconnected.
l
Request All Data at Scan Rate: This mode forces tags to be scanned at the specified rate for subscribed clients. The valid range is 10 to 99999990 milliseconds. The default is 1000 milliseconds.
l l
Do Not Scan, Demand Poll Only: This mode does not periodically poll tags that belong to the device nor perform a read to get an item's initial value once it becomes active. It is the client's responsibility to poll for updates, either by writing to the _DemandPoll tag or by issuing explicit device reads for individual items. For more information, refer to "Device Demand Poll" in server help.
Respect Tag-Specified Scan Rate: This mode forces static tags to be scanned at the rate specified in their static configuration tag properties. Dynamic tags are scanned at the client-specified scan rate.
Initial Updates from Cache: When enabled, this option allows the server to provide the first updates for newly activated tag references from stored (cached) data. Cache updates can only be provided when the new item reference shares the same address, scan rate, data type, client access, and scaling properties. A device read is used for the initial update for the first client reference only. The default is disabled; any time a client activates a tag reference the server attempts to read the initial value from the device.
Device Properties - Ethernet Encapsulation
Ethernet Encapsulation is designed to provide communication with serial devices connected to terminal servers on the Ethernet network. A terminal server is essentially a virtual serial port. The terminal server converts TCP/IP messages on the Ethernet network to serial data. Once the message has been converted to a serial form, users can connect standard devices that support serial communications to the terminal server.
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Allen-Bradley DF1 Driver
For more information, refer to "How to... Use Ethernet Encapsulation" in server help.
Ethernet Encapsulation is transparent to the driver; configure the remaining properties as if connecting to the device directly on a local serial port.
IP Address: This property is used to enter the four-field IP address of the terminal server to which the device is attached. IPs are specified as YYY.YYY.YYY.YYY. The YYY designates the IP address: each YYY byte should be in the range of 0 to 255. Each serial device may have its own IP address; however, devices may have the same IP address if there are multiple devices multi-dropped from a single terminal server.
Port: This property is used to configure the Ethernet port to be used when connecting to a remote terminal server.
Protocol: This property is used to select either TCP/IP or UDP communications. The selection depends on the nature of the terminal server being used. The default protocol selection is TCP/IP. For more information on available protocols, refer to the terminal server's help documentation.
Notes
1. With the server's online full-time operation, these properties can be changed at any time. Utilize the
User Manager to restrict access rights to server features and prevent operators from changing the properties.
2. The valid IP Address range is greater than (>) 0.0.0.0 to less than (<) 255.255.255.255.
Device Properties - Timing
The device Timing properties allow the driver's response to error conditions to be tailored to fit the application's needs. In many cases, the environment requires changes to these properties for optimum performance. Factors such as electrically generated noise, modem delays, and poor physical connections can influence how many errors or timeouts a communications driver encounters. Timing properties are specific to each configured device.
Communications Timeouts
Connect Timeout: This property (which is used primarily by Ethernet based drivers) controls the amount of time required to establish a socket connection to a remote device. The device's connection time often takes longer than normal communications requests to that same device. The valid range is 1 to 30 seconds. The default is typically 3 seconds, but can vary depending on the driver's specific nature. If this setting is not supported by the driver, it is disabled.
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Allen-Bradley DF1 Driver
Note: Due to the nature of UDP connections, the connection timeout setting is not applicable when communicating via UDP.
Request Timeout: This property specifies an interval used by all drivers to determine how long the driver waits for a response from the target device to complete. The valid range is 50 to 9,999,999 milliseconds
(167.6667 minutes). The default is usually 1000 milliseconds, but can vary depending on the driver. The default timeout for most serial drivers is based on a baud rate of 9600 baud or better. When using a driver at lower baud rates, increase the timeout to compensate for the increased time required to acquire data.
Retry Attempts: This property specifies how many times the driver retries a communications request before considering the request to have failed and the device to be in error. The valid range is 1 to 10. The default is typically 3, but can vary depending on the driver's specific nature. The number of retries configured for an application depends largely on the communications environment.
Timing
Inter-Request Delay: This property specifies how long the driver waits before sending the next request to the target device. It overrides the normal polling frequency of tags associated with the device, as well as one-time reads and writes. This delay can be useful when dealing with devices with slow turnaround times and in cases where network load is a concern. Configuring a delay for a device affects communications with all other devices on the channel. It is recommended that users separate any device that requires an interrequest delay to a separate channel if possible. Other communications properties (such as communication serialization) can extend this delay. The valid range is 0 to 300,000 milliseconds; however, some drivers may limit the maximum value due to a function of their particular design. The default is 0, which indicates no delay between requests with the target device.
Note: Not all drivers support Inter-Request Delay. This setting does not appear if it is not available.
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Device Properties - Auto-Demotion
The Auto-Demotion properties can temporarily place a device off-scan in the event that a device is not responding. By placing a non-responsive device offline for a specific time period, the driver can continue to optimize its communications with other devices on the same channel. After the time period has been reached, the driver re-attempts to communicate with the non-responsive device. If the device is responsive, the device is placed on-scan; otherwise, it restarts its off-scan time period.
Demote on Failure: When enabled, the device is automatically taken off-scan until it is responding again.
Tip: Determine when a device is off-scan by monitoring its demoted state using the _AutoDemoted system tag.
Timeouts to Demote: Specify how many successive cycles of request timeouts and retries occur before the device is placed off-scan. The valid range is 1 to 30 successive failures. The default is 3.
Demotion Period: Indicate how long the device should be placed off-scan when the timeouts value is reached. During this period, no read requests are sent to the device and all data associated with the read www. ptc.com
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Allen-Bradley DF1 Driver requests are set to bad quality. When this period expires, the driver places the device on-scan and allows for another attempt at communications. The valid range is 100 to 3600000 milliseconds. The default is 10000 milliseconds.
Discard Requests when Demoted: Select whether or not write requests should be attempted during the off-scan period. Disable to always send write requests regardless of the demotion period. Enable to discard writes; the server automatically fails any write request received from a client and does not post a message to the Event Log.
Device Properties - Protocol Settings
Error Checking Method: There are two methods of error checking available: Block Check Character (BCC) and 16-bit Cyclic Redundancy Check (CRC). Choose the checksum method expected by the device or the device does not respond.
Swap Float Words: Allen-Bradley PLC-5 devices always transfer the upper word first followed by the lower word, so the Float words must be swapped. This is the default setting. If the device transfers the lower word first, the upper word in the packet on the serial link does not require word swapping.For more information,
see
Float Words
.
Request Size: Define or change the amount of data requested, which is important in refining application performance. If the application accesses large areas of PLC memory consecutively, a large request size may be beneficial. If the data is spread throughout the PLC, a small request size may be beneficial. The default setting is Large.
N File Float Access: Select whether the driver natively supports Float access to Integer Files. The default setting is Enable.
Float Words
PLC-5 Floats follow the IEEE 754 standard. They contain a sign bit S, an exponent E and a mantissa M. The
32-bit layout of this IEEE 754 Float is as shown below.
Upper Word Lower Word
SEEEEEEE EMMMMMMM MMMMMMMM MMMMMMMM
Byte 3 Byte 2 Byte 1 Byte 0
Allen-Bradley PLC-5 devices transfer binary Floating-point data on the serial link in the following order:
Upper Word Lower Word
Byte 2 Byte 3 Byte 0 Byte 1 www. ptc.com
Allen-Bradley DF1 Driver
This means the upper word is received first, followed by the lower word. Due to this ordering, a swap of the words is required, providing:
Lower Word Upper Word
Byte 0 Byte 1 Byte 2 Byte 3
The result passed on to the client is as follows:
Byte 3 Byte 2 Byte 1 Byte 0
Some PLC-5 emulated devices (such as the Avtron ADDvantage-32) already transfer binary Floating point data on the serial link with the lower word first.
Lower Word Upper Word
Byte 0 Byte 1 Byte 2 Byte 3
In this case, no order swap is required. The result passed on to the client is as follows:
Byte 3 Byte 2 Byte 1 Byte 0
Generally is if the device transfers the lower word first, the upper word in the packet on the serial link does not require word swapping. This only applies to PLC-5 emulated devices; that is, devices that use the Allen-
Bradley DF1 protocol with PLC-5 commands. Allen-Bradley PLC-5 devices always transfer the upper word first followed by the lower word so the Float words must be swapped.
Function File Options
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For applicable function files, data can be written to the device in a single operation. By default, when data is written to a function file sub element (field within the function file structure), a write operation occurs immediately for that tag. For such files as the RTC file, whose sub elements include hour (HR), minute (MIN) and second (SEC), individual writes are not always acceptable. With such sub elements relying solely on time, values must be written in one operation to avoid time elapsing between sub elements writes. For this reason, there is the option to "block write" these sub elements.
Applicable Function Files/Sub Elements
RTC
Year
Month
Day
Day of Week
Hour
YR
MON
DAY
DOW
HR www. ptc.com
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Allen-Bradley DF1 Driver
RTC
Minute
Second
MIN
SEC
How Block Writes Work
Block writing involves writing to the device the values of every Read/Write sub element in the function file in a single write operation. It is not necessary to write to every sub element prior to performing a block write.
Sub elements not affected (written to) have the current value written back to them. For example, if the current (last read) date and time is 1/1/2001, 12:00.00, DOW = 3, and the hour is changed to 1 o'clock, then the values written to the device would be 1/1/2001, 1:00.00, DOW = 3.
Instructions
1. Go to the Function File Options in the device properties. Enable Allow Function File Block Writes.
This notifies the driver to utilize block writes on function files supporting block writes. The changes are effective immediately after clicking OK or Apply.
2. Write the desired value to the sub element tag(s) in question. The sub element tag(s) immediately takes on the value(s) written to it.
Note: After a sub element is written to at least once in block write mode, the tag's value does not originate from the controller, but instead from the driver's write cache. After the block write is done, all sub element tag values originate from the controller.
3. Once the entire desired sub elements are written to, the block write that sends these values to the controller may be performed. To instantiate a block write, reference tag address RTC:<element>._
SET. Setting this tag's value to "True" causes a block write to occur based on the current (last read) sub elements and the sub elements affected (written to). The _SET tag is treated as a Write Only tag; meaning, a write to this tag is not reflected in subsequent reads on it. Setting this tag's value to
"False" performs no action.
Function files are structure-based files, similar to PD and MG data files, and are unique to the Micrologix
1200 and 1500.
For more information on a specific function file are supported in the Allen-Bradley DF1 Driver, select a link from the list below.
Slot Configuration
SLC500 models (with modular I/O racks) must be configured for use with this driver if the I/O is to be accessed by the driver. Up to 30 slots can be configured per device.
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Allen-Bradley DF1 Driver
To use the slot configuration, follow the instructions below:
1. Select the slot to be configured by clicking on the row in the module list box.
2. To select a module, click on it from the available modules drop-down list.
3. Configure the Input Words and Output Words if necessary.
4. To remove a slot/module, select No Module from the available modules drop-down list.
5. When complete, click OK.
Tip: Use the 0000-Generic Module to configure I/O that is not contained in the list of Available Modules.
Note: It is common to have open slots in the rack that do not contain a physical module. To correctly access data for the various slots that do contain a module, the preceding module(s) must have the correct number of words mapped. For example, if only interested in the I/O in slot 3, but slots 1 and 2 contain I/O modules, the correct modules must be selected for slots 1, 2, and 3 from this slot configuration group.
0000-Generic Module
Use the Generic Module to map Input and Output words for modules that are not represented in the list of available modules. To correctly use the Generic Module, users must know the number of Input and Output words required for each module.
Consult Allen-Bradley I/O user manual documentation to confirm Input and Output requirements and be aware that requirements may be different based on Class 1 or Class 3 operation.
For information on the number of input and output words available for each I/O module, refer to
Modular
I/O Selection Guide
.
Modular I/O Selection Guide
The following table lists the number of input and output words available for each I/O module in the Slot
Configuration list.
Tip: Use the Generic Module to map input and output words for modules that are not represented in the list of available modules. The range of accepted values is shown in the table below. Consult the Allen-
Bradley user manual for the specific I/O module to configure to confirm input and output requirements.
Requirements may be different based on Class 1 or Class 3 operation.
Module Type
0000-Generic Module
Input Words Output Words
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Module Type
1203-SM1 SCANport Comm Module - Basic
1203-SM1 SCANport Comm Module - Enhanced
1394-SJT GMC Turbo System
1746-BAS Basic Module 500 5/01 Configuration
1746-BAS Basic Module 5/02 Configuration
1746-HS Single Axis Motion Controller
1746-HSCE High-Speed Counter/Encoder
1746-HSRV Motion Control Module
1746-HSTP1 Stepper Controller Module
1746-I*16 Any 16 pt Discrete Input Module
1746-I*32 Any 32 pt Discrete Input Module
1746-I*8 Any 8 pt Discrete Input Module
1746-IA16 16 Input 100/120 VAC
1746-IA4 4 Input 100/120 VAC
1746-IA8 8 Input 100/120 VAC
1746-IB16 16 Input (Sink) 24 VDC
1746-IB32 32 Input (Sink) 24 VDC
1746-IB8 8 Input (Sink) 24 VDC
1746-IC16 16 Input (Sink) 48 VDC
1746-IG16 16 Input [TTL] (Source) 5 VDC
1746-IH16 16 Input [Trans] (Sink) 125 VDC
1746-IM16 16 Input 200/240 VAC
1746-IM4 4 Input 200/240 VAC
1746-IM8 8 Input 200/240 VAC
1746-IN16 16 Input 24 VAC/VDC
1746-INI4I Analog 4 Ch. Isol. Current Input
1746-INI4VI Analog 4 Ch. Isol. Volt./Current Input
1746-INO4I Analog 4 Ch. Isol. Current Input
1746-INO4VI Analog 4 Ch. Isol. Volt./Current Input
1746-INT4 4 Ch. Isolated Thermocouple Input
1746-IO12 6 In 100/120 VAC 6 Out [Rly] VAC/VDC
1746-IO12DC 6 Input 12 VDC, 6 Output [Rly
1746-IO4 2 In 100/120 VAC 2 Out [Rly] VAC/VDC3
1746-IO8 4 In 100/120 VAC 4 Out [Rly] VAC/VDC4
1746-ITB16 16 Input [Fast] (Sink) 24 VDC
1746-ITV16 16 Input [Fast] (Source) 24 VDC
1746-IV16 16 Input (Source) 24 VDC
1746-IV32 32 Input (Source) 24 VDC
1746-IV8 8 Input (Source) 24 VDC www. ptc.com
Allen-Bradley DF1 Driver
Input Words Output Words
1
8
1
1
1
1
1
1
2
1
1
1
1
1
2
1
8
32
8
12
8
1
32
8
8
4
1
1
1
1
8
8
8
8
1
2
1
1
1
0
8
0
0
0
0
0
0
0
0
0
0
0
0
0
0
8
32
8
0
1
8
32
8
8
4
1
1
1
1
8
8
8
8
0
0
0
0
0
Allen-Bradley DF1 Driver
Module Type
1746-NI4 4 Ch Analog Input
1746-NI8 8 Ch Analog Input, Class 1
1746-NI8 8 Ch Analog Input, Class 3
1746-NIO4I Analog Comb 2 in & 2 Current Out
1746-NIO4V Analog Comb 2 in & 2 Voltage Out
1746-NO4I 4 Ch Analog Current Output
1746-NO4V 4 Ch Analog Voltage Output
1746-NR4 4 Ch Rtd/Resistance Input Module
1746-NT4 4 Ch Thermocouple Input Module
1746-NT8 Analog 8 Ch Thermocouple Input
1746-O*16 Any 16 pt Discrete Output Module
1746-O*32 Any 32 pt Discrete Output Module
1746-O*8 Any 8 pt Discrete Output Module
1746-OA16 16 Output (Triac) 100/240 VAC
1746-OA8 8 Output (Triac) 100/240 VAC
1746-OAP12 12 Output [Triac] 120/240 VDC
1746-OB16 16 Output [Trans] (Source) 10/50 VDC
1746-OB16E 16 Output [Trans] (Source) Protected
1746-OB32 32 Output [Trans] (Source) 10/50 VDC
1746-OB32E 32 Output [Trans] (Source) 10/50 VDC
1746-OB6EI 6 Output [Trans] (Source) 24 VDC
1746-OB8 8 Output [Trans] (Source) 10/50 VDC
1746-OBP16 16 Output [Trans 1 amp] (SRC) 24 VDC
1746-OBP8 8 Output [Trans 2 amp] (Source) 24 VDC
1746-OG16 16 Output [TLL] (SINK) 5 VDC
1746-OV16 16 Output [Trans] (Sink) 10/50 VDC
1746-OV32 32 Output [Trans] (Sink) 10/50 VDC
1746-OV8 8 Output [Trans] (Sink) 10/50 VDC
1746-OVP16 16 Output [Trans 1 amp] (Sink) 24VDC3
1746-OW16 16 Output [Relay] VAC/VDC
1746-OW4 4 Output [Relay] VAC/VDC
1746-OW8 8 Output [Relay] VAC/VDC
1746-OX8 8 Output [Isolated Relay] VAC/VDC
1747-DCM Direct Communication Module (1/2 Rack)
1747-DCM Direct Communication Module (1/4 Rack)
1747-DCM Direct Communication Module (3/4 Rack)
1747-DCM Direct Communication Module (Full Rack)
1747-DSN Distributed I/O Scanner 30 Blocks
1747-DSN Distributed I/O Scanner 7 Blocks www. ptc.com
Input Words Output Words
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
4
8
8
8
0
8
16
2
2
0
0
4
0
0
0
0
0
0
2
6
8
32
8
1
1
1
1
1
1
2
2
1
1
1
1
1
1
1
2
0
8
8
8
4
8
12
2
2
4
1
4
1
1
1
1
2
1
2
6
8
32
8
28
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Module Type
1747-KE Interface Module, Series A
1747-KE Interface Module, Series B
1747-MNET MNET Network Comm Module
1746-QS Synchronized Axes Control Module
1747-QV Open Loop Velocity Control
1747-RCIF Robot Control Interface Module
1747-SCNR ControlNet SLC Scanner
1747-SDN DeviceNet Scanner Module
1747-SN Remote I/O Scanner
AMCI-1561 AMCI Series 1561 Resolver Module
Device Properties - Redundancy
Allen-Bradley DF1 Driver
Input Words Output Words
1
8
32
32
32
8
0
32
8
32
0
8
32
32
32
8
0
32
8
32
Redundancy is available with the Media-Level Redundancy Plug-In.
Consult the website, a sales representative, or the user manual for more information.
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