Acromag, Incorporated 30765 S Wixom Rd, PO Box 437, Wixom, MI 48393-7037 USA Tel: 248-295-0880 Fax: 248-624-9234 www.acromag.com Honeywell Trendview Recorder & Acromag 967EN Modbus/TCP Module as Remote I/O Contents: page Summary 2 Assumptions 3 Requirements 3 Overview of Trendview Functions 3 Acromag setup 4 Trendview setup 7 Testing 14 Notes 17 Acromag manual s Modbus maps 18 Copyright Acromag, Inc. Rev 1c, August 2011 8400 641 30765 S. Wixom Rd., Wixom, MI 48393 Tel: 248 295 0880 Trademarks are the property of their respective owners.
Honeywell Trendview recorder & Acromag 967EN Modbus-TCP module as remote I-O Summary: The Acromag 967EN has 8 analog 4-20mA inputs. It is a Modbus/TCP slave, ideal for use as remote I/O with a Honeywell paperless Trendview recorder that runs as a Modbus/TCP master over a standard Ethernet network connection. The Acromag 967EN provides data in either floating point or signed integer formats. Signed integers values range 1 to 20,000 counts across the 4-20mA input span, so scaling to user friendly engineering units has to be done on the recorder. Floating point values can be scaled to engineering units in the Acromag and read directly as scaled values. If the scaling in the Acromag is correct, no scaling is needed in the recorder's pen math. Acromag setup is done via web browser, no software is needed. Typical input and scaling setup changes made in the web browser are downloaded and executed quickly, on the order of seconds. An ON-OFF power cycle is not required for input configuration changes. Acromag's sample time is 8mS, so the Acromag data tends to be noisier than the same signal wired into a recorder. The solution is to let the Acromag average multiple samples. Start with 20 as a number to average with. The 200 ohm 4-20mA analog input resistance will not unduly load a loop powered circuit, but will inhibit HART communications (HART requires 230 ohms, minimum). Acromags i2o remote messaging function writes values only to other Acromag products. Hence, i2o is not applicable for use with Trendview. 2
Assumptions: The implementer has - familiarity navigating the Trendview X series recorder setup menus - familiarity with ethernet network connections (devices on the same subnet) - familiarity with engineering unit scaling of industrial signals Requirements: The Trendview needs sufficient credits to enable the Modbus master, including - 10 credits for Modbus master - 4 credits for full function math (script math is acceptable, standard math is not) - as many credits as needed to enable a 'pen' for each Modbus value read from the Acromag and used by the Trendview. Unused analog input pens can be used for Modbus data. Extra or virtual pens are enabled by credits. 1 credit enables 2 extra/virtual pens. Additional credits can be purchased from a Honeywell distributor, if need be. This application note applies only to Honeywell X Series Trendview recorder with firmware versions FK or above, (latest firmware version is strongly recommended). Versions CU to FK were buggy. Earlier V4 or V5 Trendview recorders did not have a Modbus Master option and cannot be used with Acromag Modbus slaves. Overview of Trendview functions: All Trendview recorders have an Ethernet port that can be enabled to run as a Modbus master. When configured, the Trendview s Modbus master will issue a Modbus request to the Acromag Modbus slave for data. The Acromag s response can provide from 1 to as many as 62 Modbus values in one Modbus message (967EN handles only 8 analog signals). The recorder assigns each received Modbus value an SCV math value; math statement SCV[x,y,z]. This math statement is used in configuring pen 'math' as the source for the pen's data. As pen data, the Modbus value can be used in any useable Trendview form. All the configuration parameters done in the Acromag s web browser can be done via Modbus, but this app note only addresses the critical function of fetching the data. Trendview uses Acromag s published Modbus decimal register values 3
Acromag Setup: Power the Acromag (24Vdc). Plug in an Ethernet cable, straight CAT5 cable to PC works OK (crossover not needed). Assign the Acromag a working static IP address - The Acromag default IP address is 128.1.1.100 - Get your PC s ethernet port onto the same subnet: 128.1.1.x - Launch a web browser (Internet Explorer) - open 128.1.1.100 - log-in default user: User (capital U) default password: password00 (lower case,.... zero zero) - Browse to the Network Configuration web page - Enter the working IP address (192.168.1.99 in this example) and click submit button - Change PC s IP address to get it back to its working subnet (192.168.1.xx in this example) 4
- Log back into the Acromag on its new working IP address/subnet via browser User: User password: password00 - Navigate to the Input Configuration web page - Select a channel (each channel is independently configured) - Select input type (typically 4-20mA) - If reading floating point, Acromag s scaling can be used. The values are IEEE 754 formatted, perfect for either Honeywell FPLB or FP B byte order formats. Enter the zero and span range scale values. 5
- If reading integer formatted values, Acromag s scaling has no effect. The Acromag s integer values are 0-20,000 ranged over 4-20mA range. So, for reading integer format, skip the ranging. - then submit: click Channel Configuration Submit Average: - average 20 samples, submit Floating Point Control: (do not enable if reading integer format) - Select Enable Floating Point Support; submit - Select floating point byte order B1,B0,B3,B2, submit (corresponds with Trendview s Modbus-X, FP B format and byte order) - be sure to fill in the scaling values for the input range (example 0-500 gpm), submit Conclude by submitting latest or all changes: 6
Trendview setup: Screen shots shown below are from a QX recorder. This same setup applies to all model Trendviews (SX, QX, QXe). 1) Confirm that recorder is on the same subnet (xxx.xxx.xxx.yyy) as the Acromag. Ethernet port setup: 2) Enable credits for Modbus master, full or scripting math, and extra pens for each Modbus value that will be polled and used. (16 pens uses 8 credits; 8 pens use 4 credits) 7
Enable Modbus master as shown below: Open and configure Slave 1 (or whichever Slave is available) as shown below: Give Slave x an appropriate Friendly Name (Acromag 967EN is example). network name = Acromag IP address There are four separate Trendview transaction setups in this app note. Pick only one. 1) Floating point format, Modbus-X FP B read Input register function code 04 * 2) Floating point format, Modbus FPLB read Holding register function code 03 3) Integer format, read Input register function code 04 4) Integer format, read Holding register function code 03 * recommended Note: Selecting integer format mandates (requires) Trendview scaling of the 0-20,000 count data value provided by the Acromag. 8
1) Floating Point Format, Read Input Register function code 04 Open a Transaction. Unassigned Transactions show up as red X, pick one. Select: Green check mark enables the transaction In selects a read operation (reads data into the recorder) Input Registers(4) selects function code 04 IEEE float selects the floating point format under Protocol on Slave X screen 3018 is the indexed decimal starting address 43018 for first of 8 analog values 8 as the number of integer registers to be read in a single transaction First value uses math statement SCV[1,1,1] Second value uses math statement SCV[1,1,2] Third value uses math statement SCV[1,1,3] Use Acromag s Input Configuration web page to configure scaling for the data value. The protocol selection (on Trendview s Slave x screen) must match Acromag s Floating Point byte order choice Bw,Bx,By,Bz. A mismatch produces unusable results. matches Acromag matches Acromag 9
2) Floating Point Format, Read Holding Register function code 03 Open a Transaction. Unassigned Transactions show up as red X, pick one. Select: Green check mark enables the transaction In selects a read operation (reads data into the recorder) Holding Registers(3) selects function code 03 IEEE float selects the floating point format under Protocol on Slave X screen 3034 is the indexed decimal starting address 43034 for first of 8 analog values 8 as the number of integer registers to be read in a single transaction First value uses math statement SCV[1,1,1] Second value uses math statement SCV[1,1,2] Third value uses math statement SCV[1,1,3], etc Use Acromag s Input Configuration web page to configure scaling for the data value. The protocol selection (on Trendview s Slave x screen) must match Acromag s Floating Point byte order choice, Bw,Bx,By,Bz. matches Acromag A mismatch produces unusable results. matches Acromag 10
3) Integer Format, Read Input Register function code 04 Open a Transaction. Unassigned Transactions show up as red X, pick one. Select: Green check mark enables the transaction In selects a read operation (reads data into the recorder) Input Registers(4) selects function code 04 Signed 16 bit int selects the compatible integer format for data in the Acromag 18 is the indexed decimal starting address 30018 for first of 8 analog values 8 as the number of integer registers to be read in a single transaction First value uses math statement SCV[1,1,1] Second value uses math statement SCV[1,1,2] Third value uses math statement SCV[1,1,3], etc Scaling Example: the 0-20,000 count is scaled 0-500 gpm (divide SCV value by 40): 11
4) Integer Format, Read Holding Register function code 03 Open a Transaction. Unassigned Transactions show up as red X, pick one. Select: Green check mark enables the transaction In selects a read operation (reads data into the recorder) Holding Registers(3) selects function code 03 Signed 16 bit int selects the compatible integer format for data in the Acromag 34 is the indexed decimal starting address 30034 for first of 8 analog values 8 as the number of integer registers to be read in a single transaction First value uses math statement SCV[1,1,1] Second value uses math statement SCV[1,1,2] Third value uses math statement SCV[1,1,3] Scaling Example: the 0-20,000 count is scaled 0-500 gpm (divide SCV value by 40): 12
Testing Acromag s Test page shows real-time, live updates of the analog input signals and the scaled conversion values, which are the values that should appear when reading floating point values in the Trendview. Trendview Trendview pen values will appear as DPM (digital) values, trend graph or bar graph values, as selected on screen layouts: 13
Communications diagnostics Path: Menu > Status > Diagnostics > Comms > Modbus 14
Modscan32: A generic Modbus master application, like Modscan32 reads Acromag Function Code 04, read Input Registers: Note that the integer value at 30018 is 10002 counts, equivalent to 12.0mA. The floating point register at 30034 is scaled to engineering units in gpm 15
Function Code 03, read Holding Registers: Note that the integer value at 30018 is 10002 counts, equivalent to 12.0mA. The floating point register at 30034 is scaled to engineering units in gpm: 16
Notes: 1) The Acromag 967EN is a Modbus/TCP slave in a desktop test easily supported two Modbus/TCP connections from two Modbus masters (Trendview and Modscan32, each at one second polling rates). 2) The Trendview can read up to 62 floating point (124 integer) values in a single Modbus master transaction, when located in contiguous registers. The recommendation is to read all of the Acromag 967EN s 8 values in a single transaction. The internal memory allocated for Modbus registers is fixed so there is no downside to fetching multiple values in a single read transaction. 3) Analog calibration can be done on the Acromag, or a 'loop calibration' can be done with Trendview's single point (offset) or dual point compensation (y=mx+b). 4) Differences between commercial and industrial Acromag modules: 5) References to Trendview s Modbus maps are irrelevant because the Trendview runs as a Modbus master. 17
Acromag manual references Data representation: Modbus register maps: A) Input registers read with function 04 Data values in integer format reside in Input registers starting at 30018 decimal Data values in Floating point format reside in Holding registers starting at 30034 18
Holding registers are the identical to input register values remapped to 43xxx : Data values in integer format reside in Holding registers starting at 43018 decimal (read with function 03) Data values in Floating point format reside in Holding registers at 43034 (read with function 03) Application note courtesy of Dan Weise, Lesman Instrument Company About Acromag Acromag is a leading manufacturer of temperature transmitters and signal conditioners for use with thermocouple and RTD sensors. These instruments convert the sensor input to a proportional 4-20mA DC current, DC voltage, Modbus, Profibus, or Ethernet signal to interface with a PC, PLC, DCS, or other control equipment. Acromag has designed and manufactured measurement and control products for more than 50 years. They are an AS9100 and ISO 9001-certified international corporation with a world headquarters near Detroit, Michigan and a global network of sales representatives and distributors. Acromag offers a complete line of industrial I/O products including a variety of process instruments, signal conditioners, and distributed fieldbus I/O modules that are available with a 7-year warranty. Industries served include chemical processing, manufacturing, defense, energy, and water services. For more information about Acromag products, call the Inside Sales Department at (248) 295-0880, FAX (248) 624-9234. E-mail sales@acromag.com or write Acromag at 30765 South Wixom Road, P.O. Box 437, Wixom, MI 48393-7037 USA. The web site is www.acromag.com. 19