SST Woodhead Profibus Scanner

[Ronny_resistor 0]

I used this forum about three months ago all who helped with my Omron CJ project thanks a million to all who got involved, a lot of ideas came from this forum and it made the project bearable. About 10 years ago I did a project using Siemens s5 and a Profibus ET200 card that basically communicated to 16 drives. I remember the bit shifting I needed to do basically shift 8 bits to the left take the same word and shift the word to the right 8 times and then "and" and words together, creating a shift. (Swapping the LSB and the MSB) I know that this was done due to some Motorola and Intel chipset issues. My question is if you are using the SLC 5/04 do I need to be concerned about this bit movement ?? My second question has to do with profibus. My Vendor has supplied me with the Profibus GDS file for their system. They purchased the engineering and did everything with Siemens S7 no documentation was supplied for the AB type systems. All questions are replied with we supply the hardware and you are responsible for the programming. So I have basically 20 Input words allocated and 15 output words allocated. The words in profibus can be 8 bit 16, 24 and 32 bits. pending which register you look at (status is 16 bit) Analog reference is done via (2) 16 bit registers. Note the first 4 registers for input and output are set up for RX-SDO and TX-SDO functions. Most of this seems to be working (other than do I need a byte reversal ?) what I don't understand is how do I take 4 registers that are in Hex code and convert them to a float register. When we did everything in Siemens S5 we were programming in 16 bit software. This can't be the first time SST profibus Scanners have been utelized in AB racks. Thanks in advance to all scanner_setup.pdf Ron

[jstolaruk 9]

"I know that this was done due to some Motorola and Intel chipset issues. My question is if you are using the SLC 5/04 do I need to be concerned about this bit movement ??" I just finished a couple of projects using the SST Profibus card with a 5/04 and I did not run into this problem. "what I don't understand is how do I take 4 registers that are in Hex code and convert them to a float register." Depending on what the format is of these registers are, you may have to use some SLC math instructions to convert it. When using SLC math instructions, if the destination/result address is a floating point data file location, the conversion to floating point will be done automatically to the SLC floating point format. For instance: ADD N7:0 N7:1 F8:0 adds the contents of two data file locations of type integer and stores the result to a floating point data file location. The conversion is done by the instruction. Can you provide some more information about those registers and their format? Edited 30 Mar 2008 by jstolaruk

[Ronny_resistor 0]

Just to Update this message: The Manufacturer showed the following information: Byte 0: 4Bh (EVEN) Byte 1: 12h (ODD) Byte 2: 20h (EVEN) Byte 3: 00h (ODD) Byte 4: 00h (EVEN) Byte 5: 00h (ODD) Byte 6: 34h (EVEN) Byte 7: 78h (ODD) I finally read somewhere that the byte patern is Even Odd and will show up inside the PLC as Odd even so the PLC register has the following Byte pattern Reg:1 124B [4B represents a 16 bit response] Reg:2 0020 [20 12 represents a register within the device (TW-Empty Weight) Reg:3 0000 Reg:4 7834 [Value response of the device] note: Byte 0 could equal one of 4 service modes: 43h (4 Bytes or Float) 47h (3 Bytes, ??) 4Bh (2bytes, Integer) or 4Fh (1 byte, 8 Bits). Manufacturers definition for Bytes 4, 5, 6 and 7: "Data-Bytes of SDO telegram. By form-byte "0E" the values, contained in the data bytes, are transformed from Intel into Motorola format and vice versa. When sending or recieving values by means of the SDO-telegram the following bytes are of importance: 8 bit Value Byte 7 16 bit value Byte 6 and 7 32 bit value Byte 4 and 7" Converted German to English I am still lost as to what I am seeing as far as reel values. The information comes across as hexadecimal. I am still not sure if I need to shift the word to the left 8 bits and then shift a copied word to the right 8 times and then OR the two words. How are Hex values used in Allen Bradley PLC's The nice thing about information requests from the unit are all handelled by 20XX the 20h is the same for all information. Anyway any thoughts would be appreciated Ron

[Ronny_resistor 0]

OK i finally connected a DOS computer to the serial port and I was able to write a Value to the Profibus Scanner and see what the Device was seeing. 0001h = 256 0010h = 4096 0100h = 1 1000h = 16 This proves the received values are reversed, today i will try to interpret the values from the unit. You got to love the way this works (Give me Devicenet any day !!!) Ron