1.0 Using the DLCD on a DH-485 Network

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1 Insert No. DLCDB Drawing No. LP Released / MODEL DLCD DUAL LOOP CONTROLLER w/ DH GENERAL DESCRIPTION The Model DLCD, Dual Loop Controller with DH, has a similar feature set and specifications as the standard Dual Loop Controller. The DLCD provides a connection into an Allen Bradley DH network allowing a fully featured dual loop PID controller to be controlled and monitored by an Allen Bradley PLC (SLC controller, or similar), over a DH network. The DLCD communications port may be configured for DH, or as a programming port allowing complete programming by our Windows based RLCPro configuration software. USING THIS DOCUMENT This document is an addendum to the bulletin describing the standard DLC and describes the use of the DH connection of the DLCD. This document should be read in conjunction with the DLC Bulletin. ORDERING INFORMATION MODEL NO. DESCRIPTION PART NUMBER DLCD CBJ DRRJ Dual Loop Controller w/ DH Dual Loop Controller w/ Analog Outputs w/ DH SLC (RJ) to RJ Cable RJ Connector to Terminal Adapter DLCD DLCD CBJC DRRJT. Using the DLCD on a DH Network Overview The DLCD rapidly exchanges blocks of control and status information for each PID loop with an Integer File that has been allocated in the PLC. Each DLCD is assigned an Integer File by setting the appropriate DIP Switches on the DLCD. By accessing this Integer File, the PLC is able to control and monitor the operation of each PID loop within each DLCD. Most applications will only require information contained in these Control and Status blocks. The ability has been included to upload and download Parameter and Configuration blocks on demand for each PID loop. Integer File Structure The Integer File for each DLCD is structured to include Control, Status, Parameter and Configuration blocks for each PID Loop. Control and Status blocks contain data that is transferred automatically by the DLCD on alternate communication scans. Parameter Blocks contain DLCD operating parameters and may be occasionally changed. Configuration Blocks contain system configuration parameters and are rarely changed. Table gives the overall structure of the Integer File giving the location of the various blocks for each PID loop or channel. The tables in the following sections show the structure of each block and provide a crossreference from the Allen Bradley Integer File register to the equivalent MODBUS Holding Register in the DLCD. When using the Integer File tables in the following sections, refer to the Register Table in the DLC Bulletin for register details such as factory setting, limits and description. Note: Modbus registers provided for reference only. Block Reference.. Control Block Channel A Table.. Control Block Channel B Table.. Status Block Channel A Table.. Status Block Channel B Table.. Parameter Block Channel A Table.. Parameter Block Channel B Table.. Configuration Block Channel A Table.. Configuration Block Channel B Table Table Overview of Integer File Structure Phone:.. Fax:.. Web: info@clrwtr.com

2 Control Block The Control block contains control values and commands, such as Set Point and Control Mode. The DLCD continually reads the Control Blocks for each PID loop from the PLC providing a means whereby the PLC program can control the DLCD. Status Block The Status block contains current operating values and status such as Process Value and Input Status. The DLCD continually writes the Status Block for each PID channel providing a means whereby the PLC can monitor the operating status of the DLCD. Setpoint Channel A Process Value Channel A Output Power Channel A Output Power Channel A.. Table.... Table Table Table Setpoint Channel B Process Value Channel B Output Power Channel B Output Power Channel B.. Table.... Table Table Table Table Control Block Channel A and B Table Status Block Channel A and B Control Mode Disable Integral Action Disable Setpoint Ramping Autotune Request (See Note ).. Autotune Code Alarm Output AL (See Note ) Alarm Output AL (See Note ) Table Control Block for and Flags BITS REGISTER NAME Parameter Read Strobe (See Note ) Configuration Read Strobe (See Note ) Parameter Write Strobe (See Note ) Configuration Write Strobe (See Note ).. Input Error Status Register.. AutoTune Phase Control Output OP Control Output OP Set Point Ramping In Progress Alarm Output AL Alarm Output AL Table Status Block for and Flags Bus Active (See Note ) AutoTune In Progress (See Note ) AutoTune Done (See Note ) Parameter Block Read Acknowledge (See Note ) Configuration Block Read Acknowledge (See Note ) Parameter Block Write Acknowledge (See Note ) Configuration Block Write Acknowledge (See Note ) Table Status Block for and Flags Table Control Block for and Flags Phone:.. Fax:.. Web: info@clrwtr.com

3 Notes:. Alarm Output Control The Control flags Alarm Output AL and AL must set TRUE () for correct Alarm operation when Control Mode is Automatic (). Set to to reset an Alarm.. Autotune Request Setting the Autotune Request flag forces the DLCD to start the autotune process. Refer to section Autotune Request for more detail on how the PLC program may autotune a PID loop in the DLCD.. Read/Write Strobes Setting the Read/Write Strobe flags forces the DLCD to upload or download the appropriate Parameter or Configuration block. Refer to section Transferring Parameter and Configuration Data for more detail on how to transfer these blocks between the PLC and the DLCD.. Autotune Status Monitoring the AutoTune Done and AutoTune In Progress flags allows the PLC program to detect the completion of the Autotune process in the DLCD. Refer to section Autotune Request for more detail on how the PLC program may autotune a PID loop in the DLCD.. Bus Active Each DLCD toggles the Bus Active flag on each communication scan.. Read/Write Acknowledge The DLCD sets the appropriate acknowledge flag once the requested upload or download of the Parameter or Configuration block is complete. Refer to section Transferring Parameter and Configuration Data for more detail on how to transfer these blocks between the PLC and the DLCD.. Data flow is described with respect to the DLCD in exchanges with the PLC. Thus, Read data is data transferred from the PLC to the DLCD and Write data is data transferred from the DLCD to the PLC. Parameter Block The Parameter blocks contain values that may need to be changed while the DLCD is operating, such as PID parameters. Each Parameter Block may be uploaded to or downloaded from the PLC on demand by setting the appropriate request bit in the Control Block. Refer to section Transferring Parameter and Configuration Data to see how this is done. Proportional Band Integral Time Derivative Time Cycle Time (Cooling) Deadband (Cooling) Alarm Value Alarm Value Relative Gain (Cooling) Proportional Band Integral Time Derivative Time Cycle Time (Cooling) Deadband (Cooling) Alarm Value Alarm Value Relative Gain (Cooling) Table Parameter Block Channel A Table Parameter Block Channel B Phone:.. Fax:.. Web: info@clrwtr.com

4 Configuration Block The Configuration blocks contain values that describe the DLCD setup such as Input configuration and as such will not need to be changed during normal operation. These blocks may be uploaded to and downloaded from the PLC on demand by setting the appropriate request bit in the Control Block. Refer to section Transferring Parameter and Configuration Data to see how this is done. MODBUS REGISTER Offset Power Span Correction Offset Correction Low Limit (Setpoint) High Limit (Setpoint) Ramp Rate (Setpoint) Process Low (Scaling Points) Process High (Scaling Points) Input Low (Scaling Points) Input High (Scaling Points) Cycle Time (OP) On Delay (AL) On Delay (AL) Scaling Value Low (Analog Output) Scaling Value High (Analog Output) Direct Entry Value (Analog Output) Ramping Setpoint Value.. Table Sensor Failure Power Preset (OP) Power Low Limit (OP) Power High Limit (OP) Dampening Time (OP) On/Off Control Hysteresis (OP) Hysteresis (AL) Hysteresis (AL) Deadband (Analog Output) Update Time (Analog Output).... Table Table.. Table Action (AL) Action (AL) Table Configuration Block Channel A Offset Power Span Correction / Remote Setpoint Ratio Multiplier Offset Correction / Remote Setpoint Bias Offset Low Limit (Setpoint) High Limit (Setpoint) Ramp Rate (Setpoint) Process Low (Scaling Points) Process High (Scaling Points) Input Low (Scaling Points) Input High (Scaling Points) Cycle Time (OP) On Delay (AL) On Delay (AL) Scaling Value Low (Analog Output) Scaling Value High (Analog Output) Direct Entry Value (Analog Output) Ramping Setpoint Value.. Sensor Failure Power Preset (OP) Power Low Limit (OP) Power High Limit (OP) Dampening Time (OP) Hysteresis (AL) Deadband (Analog Output).. Action (AL) Action (AL) Table Configuration Block Channel B On/Off Control Hysteresis (OP) Hysteresis (AL) Update Time (Analog Output).... MODBUS REGISTER Table Table Table Table Remote/Local Setpoint Select Channel B Assignment (Input).. Rounding (Input) Table Configuration Block for and Flags.. Local/Remote Set Point Transfer Mode (Input).. Mode (Analog Output).. Assignment (Analog Output) Table Configuration Block for and Flags Ch. A Ch. B Reset (AL) Reset (AL) Enable Standby (AL) Enable Standby (AL).. Digital Input Filter (Input) Temperature Scale (Input) Control Action (OP) Filter (Analog Output).. Process Decimal Point (Scaling Points) Table Configuration Block for and Flags Resolution (Input).. Input Type (Input) Table Configuration Block for and Flags Phone:.. Fax:.. Web: info@clrwtr.com

5 . Setting the DIP Switches Overview The DIP Switches and the Default Serial Terminal set the DLCD serial communication operating mode to either DH mode or MODBUS mode. DH mode allows the DLCD to be connected to a DH network. MODBUS mode allows programming of the DLCD using RLCPro. DH Mode Integer File Each DLCD is assigned a unique Integer File in the PLC that the DLCD uses to transfer data. Switch A (SWA) sets the target Integer file in the range N..N. Note N and N are invalid Integer File numbers and therefore cannot be used. INTEGER FILE SWITCH POSITION COMMENT N Valid File Number N UP Invalid File Number N UP Invalid File Number N UP UP Valid File Number N UP Valid File Number.. Valid File Number N UP UP UP UP UP UP Valid File Number Table Integer File settings using DIP Switch A DLCD Address Each device on a DH network must have a unique address. Switch B (SWB) allows the DLCD address to be set in the range... DLCD Switch Position Address UP UP UP UP.. UP UP UP UP UP PLC Address The DLCD transfers data with a target PLC. Switch B (SWB) allows the address of the target PLC on the DH network to be set in the range... PLC ADDRESS SWITCH POSITION UP UP.. UP UP UP Table Selections for PLC Address using DIP Switch B Example This example shows the DIP Switch settings for a DLCD operating in DH mode with the following configuration. PLC Address : DLCD Address : Integer File : (N) UP UP UP UP Communication Settings The DLCD has a fixed baud rate of when used in DH mode. Table Selections for DLCD Address using DIP Switch B MODBUS Mode In MODBUS mode, the DLCD responds to MODBUS RTU frames and therefore allows programming using RLCPro (refer to DLC Bulletin for detailed information on using RLCPro with the DLCD). To configure the DLCD for MODBUS without changing the DIP switches, use the Default Serial Setting Terminal. DEFAULT SERIAL SETTING CONNECTIONS If using software selectable serial settings and the serial settings are unknown or forgotten, they can be temporarily reset to the defaults by connecting the Default Serial Setting terminal to Output Common terminal with a jumper. Alternatively, set all DIP switches Down as shown in Example. The DLCD leaves the factory in this state, and is therefore ready to be programmed using RLCPro. Example This example shows the DIP Switch settings for a DLCD operating in MODBUS mode with the default serial settings. Serial Communication Defaults: Protocol: RTU Data Bits: Address: Parity: none Baud Rate: Phone:.. Fax:.. Web: info@clrwtr.com

6 EXAMPLE APPLICATIONS Transferring Parameter and Configuration Data Parameter and Configuration blocks can be uploaded to and downloaded from the PLC Integer File by setting the appropriate read/write strobe in the relevant Control block. On completion of the data transfer the DLCD sets the corresponding acknowledge bit in the Status block. Figure shows a fragment of a Program File, captured from Rockwell s RSLogix that shows how the strobe and acknowledge flags may be used to download a configuration block to the DLCD. Autotune Request The Autotune Request flag allows the PLC program to start the autotune process in the DLCD. While autotuning, the DLCD sets the Autotune In Progress bit and when complete, sets the Autotune Done bit. By monitoring this bit, the PLC program is able to detect when the autotune process is complete. Figure shows a fragment of a program file, captured from RSLogix that shows how the request flag and done flag may be used to start the autotune process in the DLCD. Figure Autotune Request Figure Configuration Block Download Figure shows a fragment of a program file, captured from RSLogix that shows how the strobe and acknowledge flags may be used to upload a configuration block from the DLCD. Figure Configuration Block Upload Phone:.. Fax:.. Web: info@clrwtr.com

7 APPLICATION : SLC / AND DLCD Example showing direct connection of multiple DLCD units and a SLC /, using Red Lion Cable Jumper (CBJBD) and SLC to RJ Cable (CBJC). APPLICATION : DLCD with AIC MODULE Example showing direct connection of multiple DLCD units to Red Lion DIN Rail Mounted Terminal Connector (DRJT) allowing a variety of connection options using the AIC Module from Allen Bradley. Phone:.. Fax:.. Web: info@clrwtr.com