Ron Beaufort
Lifetime Supporting Member
I received the following in a Private Message from roomi117:
Greetings Naeem,
first of all, you should post all of your requests in the forum’s Question and Answer section ... you will get much better results when all members have a chance to respond ... next, we need more information about your project in order to give you any useful advice ...
issue #1: you said you are working on an SLC-500 ... are you sure about that? ... more likely you are working on an SLC-5/01, or SLC-5/02, or SLC-5/03, or SLC-5/04, or SLC-5/05 ... all of these are sometimes referred to by their “family name” of SLC-500 ... we need to know which processor you are using in order to help you ... it is also possible that you are working with a PLC-5 processor ... (see next issue) ...
issue #2: the 1771-IFE module that you mentioned will not fit in the same chassis with any of the small SLC-500 processors ... specifically, it is designed for use with the larger PLC-5 system ... it IS possible to use the 1771-IFE module with the smaller SLC-500 processor - but it must be done by installing the 1771-IFE in a “remote I/O” configuration ... specifically, the larger module would be installed in a separate chassis and would communicate with the SLC-500 processor over a “remote I/O” cable ... if that is what you’re trying to set up, then we need to know what “scanner” module (example: 1747-SN) and what “adapter” module you’re using (example: 1771-ASB) ... it would also help to know how your system is configured ... specifically, we need to know what “rack” and “group”, etc. your remote rack is set for ... this is done with DIP switch settings on the 1771-ASB adapter module ...
issue #3: you said that you want to connect 3 thermocouples to the 1771-IFE module ... the 1771-IFE does not accept thermocouple inputs connected directly to the module ... instead, each of the thermocouples must be connected to a separate “transmitter” ... this transmitter will take the millivolt output of the thermocouple and convert it into a 4 to 20 milliamp signal ... this 4 to 20 milliamp signal can then be connected to the 1771-IFE module ... (note: there are other ways of doing this, but this is the most common method) ... connecting the signals to the 1771-IFE will require that you have an understanding of wiring “single-ended” and “differential” signals ... are you familiar with those terms? ... and is your 1771-IFE module already configured for one method or the other? ... specifically, is the module already in use for existing signals - to which the 3 thermocouples will be added? ... note that wiring the 1771-IFE module correctly will require that you set the position of a series of small “jumpers” which are located inside the module ...
issue #4: is it possible that you meant to say that you will be using a 1771-IXE module (rather than a 1771-IFE)? ... if so, the 1771-IXE will accept thermocouple inputs wired directly to the module ...
issue #5: in any event, we’ll need to know what type of thermocouples you’ll be using ... example: type J, type K, etc. ... if you’re using the 4 to 20 milliamp transmitter method, then we’ll also need to know the scaling for your system ... example: 4 milliamps equals 32 degrees Fahrenheit ... 20 milliamps equals 212 degrees Fahrenheit ... etc. ...
issue #6: all of these issues must be covered before we can offer you any specific examples of programming code ... but a basic idea is this: you must “configure” the 1771-IFE module with a BTW (Block Transfer Write) command rung ... this will force the processor to send a block of several words of data to the 1771-IFE module to tell it how it is expected to perform (scaling, number format, etc.) ... then you must program a BTR (Block Transfer Read) command rung which will execute repeatedly ... this will force the processor to retrieve information from the 1771-IFE module and place the information in the processor’s memory table - usually in a series of Integer-type locations ... if all else is done correctly, the readings from all 3 thermocouples will be contained in that one block of information ... example: in words N7:54, N7:55, and N7:56 ... normally the readings are all scaled from 0 to 4095 as raw data ... then we usually program separate math functions to scale the data into readings of degrees Fahrenheit or Celsius ... or it is also possible to “configure” the 1771-IFE module to provide the scaling internally ...
as you can see, the task that you have outlined is not a trivial undertaking ... but if you’ll be good enough to give us all of the details about your system, we’ll be glad to try to help ... personally, I’ll be offline and unavailable most of next week ... so I am posting your request on the forum’s main Question and Answer board in the hopes that some other members will be able to help you ...
I hope that this information will help get you started ... I wish you good luck ...
Greetings Naeem,
first of all, you should post all of your requests in the forum’s Question and Answer section ... you will get much better results when all members have a chance to respond ... next, we need more information about your project in order to give you any useful advice ...
issue #1: you said you are working on an SLC-500 ... are you sure about that? ... more likely you are working on an SLC-5/01, or SLC-5/02, or SLC-5/03, or SLC-5/04, or SLC-5/05 ... all of these are sometimes referred to by their “family name” of SLC-500 ... we need to know which processor you are using in order to help you ... it is also possible that you are working with a PLC-5 processor ... (see next issue) ...
issue #2: the 1771-IFE module that you mentioned will not fit in the same chassis with any of the small SLC-500 processors ... specifically, it is designed for use with the larger PLC-5 system ... it IS possible to use the 1771-IFE module with the smaller SLC-500 processor - but it must be done by installing the 1771-IFE in a “remote I/O” configuration ... specifically, the larger module would be installed in a separate chassis and would communicate with the SLC-500 processor over a “remote I/O” cable ... if that is what you’re trying to set up, then we need to know what “scanner” module (example: 1747-SN) and what “adapter” module you’re using (example: 1771-ASB) ... it would also help to know how your system is configured ... specifically, we need to know what “rack” and “group”, etc. your remote rack is set for ... this is done with DIP switch settings on the 1771-ASB adapter module ...
issue #3: you said that you want to connect 3 thermocouples to the 1771-IFE module ... the 1771-IFE does not accept thermocouple inputs connected directly to the module ... instead, each of the thermocouples must be connected to a separate “transmitter” ... this transmitter will take the millivolt output of the thermocouple and convert it into a 4 to 20 milliamp signal ... this 4 to 20 milliamp signal can then be connected to the 1771-IFE module ... (note: there are other ways of doing this, but this is the most common method) ... connecting the signals to the 1771-IFE will require that you have an understanding of wiring “single-ended” and “differential” signals ... are you familiar with those terms? ... and is your 1771-IFE module already configured for one method or the other? ... specifically, is the module already in use for existing signals - to which the 3 thermocouples will be added? ... note that wiring the 1771-IFE module correctly will require that you set the position of a series of small “jumpers” which are located inside the module ...
issue #4: is it possible that you meant to say that you will be using a 1771-IXE module (rather than a 1771-IFE)? ... if so, the 1771-IXE will accept thermocouple inputs wired directly to the module ...
issue #5: in any event, we’ll need to know what type of thermocouples you’ll be using ... example: type J, type K, etc. ... if you’re using the 4 to 20 milliamp transmitter method, then we’ll also need to know the scaling for your system ... example: 4 milliamps equals 32 degrees Fahrenheit ... 20 milliamps equals 212 degrees Fahrenheit ... etc. ...
issue #6: all of these issues must be covered before we can offer you any specific examples of programming code ... but a basic idea is this: you must “configure” the 1771-IFE module with a BTW (Block Transfer Write) command rung ... this will force the processor to send a block of several words of data to the 1771-IFE module to tell it how it is expected to perform (scaling, number format, etc.) ... then you must program a BTR (Block Transfer Read) command rung which will execute repeatedly ... this will force the processor to retrieve information from the 1771-IFE module and place the information in the processor’s memory table - usually in a series of Integer-type locations ... if all else is done correctly, the readings from all 3 thermocouples will be contained in that one block of information ... example: in words N7:54, N7:55, and N7:56 ... normally the readings are all scaled from 0 to 4095 as raw data ... then we usually program separate math functions to scale the data into readings of degrees Fahrenheit or Celsius ... or it is also possible to “configure” the 1771-IFE module to provide the scaling internally ...
as you can see, the task that you have outlined is not a trivial undertaking ... but if you’ll be good enough to give us all of the details about your system, we’ll be glad to try to help ... personally, I’ll be offline and unavailable most of next week ... so I am posting your request on the forum’s main Question and Answer board in the hopes that some other members will be able to help you ...
I hope that this information will help get you started ... I wish you good luck ...
