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There are so many settings that can cause Modbus RTU to not work. It pays to read a value from a slave before writing a value to a slave. Can you successfully read the value in (4)0031?

DeltaV is a DCS, ControlLogix is a PLC. ARC Advisory Group is surveying readers on LinkedIN at this link: https://www.linkedin.com/groups/1967039/ and appropriately, DeltaV appears in the list, ControlLogix does not, but A-B's PlantPAx does appear in the list. There are distinct...

>I am installing a high speed IO card, but it doesn't have HART >capabilities. Which solutions do I have to avoid this problem? Only >handheld? Use of two IO cards? It is not clear what you are trying to accomplish and what you expect HART to do for your application, or what problem you...

Can you post a link to the manual (not the product brochure or spec sheet; the manual)?

You haven't listed out the things you've tried and what you've ruled out through troubleshooting. There are so many things that can cause a HART attack, that I'll just print Mr. Berge's - list of things you might not know about HART - List of design issues that can cause a HART attack...

Is the example message an RTU message (in hex) or Modbus ASCII, (also in hex)? It could be that the single byte error checksum is an LRC value, as opposed to a Modbus RTU 16 bit, two byte CRC error checksum. The example might be the 'basic Modbus polling' message in ASCII with a single...

I am not sure what is meant by 'gas'. LNG? LPG? Gasoline? I doubt commercial grade ultrasonics will handle LNG level measurement. The issues are: - speed-of-sound through natural gas vapor, not through air (which is the medium commercial units are based on). - even a...

>It is also observed that during night the level increases (from 4.00pm to 8.00am), and during day the level comes down (from 8.00am to 4.00pm). That is a classic case of unequal heating of the DP capillaries and seal fill fluids. When the low side is warmer than the high side, the...

I presume that you're really communicating with either an electric actuator or a positioner because the metal or plastic valve bodies don't talk digital protocols and only sound off when they cavitate. For testing purposes, like, writing 'drive open', 'drive closed', or 'stop' commands, or...

I'm not sure what a 'router' with a Modbus master is. What would a Modbus master router do with the data received from a slave? Route it to another slave? And if Pactware connected through COM4 (232), how did it send and receive data, yet 'the device is not supported'? The two statements...

>The connection is simmilar as for level gauge. I don't know what you mean by that. Does the DP transmitter flange mount directly at the bottom of the tank and use a single capillary remote seal for the vapor space pressure measurement? Or is the transmitter a dual (Two) remote seal...

The 19197 value might also be an integer representation of 16 bits of a 32bit floating point value.

Modbus just carries the bits from the slave to the master. It's up to the application (not Modbus) to interpret the bits. Knowing what the bits represent is the first step. I can't tell you what 19197 represents (but it looks like a single 16 bit Modbus register integer value). You need...

Oops, 2nd post, data format explanation should read: . . . the high order byte is the COMMAND "Code" (not value), and the low order byte is the COMMAND's value.

The example Operation Command in the link: https://postimg.cc/bGm0j7ZX uses the Function Code 06, with a register address of 0000, but register address 0000 is (4)0001 and according to the register table/map is (4)0001, 0000 hex, is used for the 32 bit (4 byte) process variable. Is...

Not my best day reading an ASCII table . . . 33 31 0D 0A is indeed Hex representation of ASCII for 3 1 CR LF; my bad.

The 33 31 13 10 is the decimal representation of the ASCII characters. The same characters in hex are 51 49 0D 0A The 'wrong' reply characters that you sometimes get, C6 24 24 C1, must be hexadecimal representations of the received characters because C6 and C1 are not decimal. Sorry, I...

Change the A and B driver line connections on one end. The labeling of the lines is not standardized. If connected backwards, it won't damage the drivers but it won't work.

> The level measurement is constant in local level gauge. Only variation in DP type level transmitter. If this is true, then the mass of the naptha in the tank is sufficient that minor ambient temperature changes do not significantly affect its density so that the physical level remains...

1. You expect the reply to be ASCII four characters 3 1 CR LF, correct? What four characters do you actually get? 2. ASCII is usually 7 bit. Is your serial setup configured for 7 bit words?