7/6/2020 5:31 PM | |
Joined: 2/1/2019 Last visit: 1/4/2024 Posts: 31 Rating: (1) |
Hi, everybody! Help me, please. There is SITRANS LUT440, for measuring flow water in the tank. This device is connected to HART<->ModBUS converter - HRT-710. LUT440 ----> (HART) HRT-710 (RS 232) -----> (COM port) nootebook By ModBUS RTU I can get some values on the notebook, from SITRANS LUT440. (Using software - ModBUS Pool): - current milliampers - current measured PRIMARY value (flow of water) - current water level (millimeters) Also, on display LUT440 there are: (1) summary calculated flow: - for all time of work - for today Also, by connecting to the LUT440 USB port, by web browser, I can see the value of properties: (2) summary time of work: - sensor - device The question: Can I get value (1) and (2) by Modbus on notebook? What adresses i must to use to get this values by the ModBus RTU protocol? UPDATE: Summary time of work - can be readed by HART command #131 (Uint32 values - SECONDS of worktime) Summary calculated Flow - can be readed by HART command #252:
Special Thanks to my colleague - Yriy G. AttachmentSITRANS_LUT400_HART_COM.pdf (520 Downloads) |
Last edited by: 4phh at: 07/07/2020 07:34:11Last edited by: 4phh at: 02/22/2021 12:16:15 |
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7/6/2020 9:41 PM | |
Joined: 3/28/2010 Last visit: 9/21/2024 Posts: 1056 Rating: (213)
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Question: Are the totalizer values that are shown in the display available via Modbus RTU using the Moore Industries HCS module? Answer: Probably not, most likely, No. Reasons why: 1. Summary statement in Siemens LUT400 communication guide "Access to variables from HART commands" function is a No in the table at the back of the SITRANS LUT400 Communications Options application guide (document #AG091712, attached). The document has multiple communication option examples. The last example covers Modbus RTU using the Moore Industries Data Concentrator. There is a table at the back of the document describing which method gets which data, screen shown below. [snip] The Modbus method gets only the PV and Secondary Variable. It is most likely that Primary and secondary refers to the values selected for the display, as shown in this screen shot from the manual (there's potential confusion with the Primary and secondary HART variables.) https://i.postimg.cc/tTgGrT0M/LCD-display-primary-and-secondary-mode-variables.jpg The "Access to variables from HART commands" function is a No, which as the explantion below concludes, exempts the totals from access via Modbus, because totals are accessed with the HART command #252; the totals are not assignable to the four HART P/S/T/Q variables. 2. Moore HCS HART module has no "HART Command xxx" function A skim read of the Moore HART modules has references the four HART variables that I call the HART P/S/T/Q variables, but there is no mention of any method of assigning any of the extended HART variables to the P/S/T/Q variables. The totalizer is an 'extended' HART variable, accessed with Command #252, according to the "HART® Field Device Specification: Siemens SITRANS LUT400 revision 1" document. See page 167 in the LUT400 HART spec manual below. totalizer The Moore HART HCS module does not appear to have provision using HART commands, other than the ability to fetch P/S/T/Q variables from multiple HART devices. 3 the Sad conclucsion IF - there are no internal Modbus slave values in the LUT400 (there are none), - AND Modbus data is limited to that which the Moore HCS module can read from the primary and secondary HART/display values, - AND those HART/Display values are the ones designated by the LUT400 primary and secondary display functions which do not include the totals, THEN my assessment is that no, LUT 400 totalizer values are not accessible via Modbus RTU. AttachmentLUT400.zip (455 Downloads) |
Last edited by: Jen_Moderator at: 07/07/2020 08:47:13Removed links and added files as an attachment. |
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