# Ablex

MrPLC Member

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## Profile Information

• Country Zambia
1. ## Monitor alarm block

I have tried something as below the issue i have is that for memory bit M100.0-100.3 am able to get the alarm response but when i trigger M100.4-100.7 the alarm does not trigger.
2. ## Monitor alarm block

Hi all, I would like to monitor the status of my alarm word (MW100) and if any bit turns from 0 to 1 then an alarm signal should be generated, am new to siemens plc and am having a tough time accomplishing this easily. In omrom CX programmer its quite easy to do. Could anyone help me on this using ladder logic, all help will be deeply appreciated.  Regards, Ablex  PS: I'm using Step 7 V5.5
3. ## How do you turn a bit on and off in data word?

IO_Rack: Thanks for the guidance, i have decided to do bit masking by using your last option of ANDW or ORW, for positive values am performing #0FFF ANDW (Result of comparison) then for negative values am performing #8000 ORW (result of comparison). This has workout great for turning bit 15 to 1 or 0. These two operations are having no alterations on the read temperature since am only using the first right most 12 bits for storing the temperature values. Your help is much appreciated.
4. ## How do you turn a bit on and off in data word?

Hi, I am using syswin and i am doing an exercise on saving and moving data. My challenge is am monitoring temperature from a sensor and the range is -20'C to 100'C from the 4-20mA sensor, after conversion and testing for positive and negative the values are stored in D205. (I have done the conversion and testing for positive and negative values only assigning of bit 15 in D205 is left) The simple program has to turn on Bit 15 if the value is supposed to be negative. 1000 0000 0000 0001, a simple approach to telling us this is -1’C.  0000 0000 0000 0001, is telling us this is 1’C. Bit 15 is going to be our Sign Flag, so we have to ensure that if the temperature is positive then  Bit 15 = 0, how can we do this make Bit 15 of D205 = 0? If the temperature is negative then  Bit 15 = 1, how can we do this make Bit 15 of D205 = 1? How can i turn on this bit inside a data word? for negative i thought i could just add #8000 to the values after conversion then storing in D205 but for positive values how do i ensure that bit 15 is 0? How could you approach this? Am a bit stuck, all thoughts and ideas are much appreciated if possible you could add a snapshot from syswin or cx-programmer. I have attached the WTANK.SWP file which can be opened in syswin or cx-programmer. Look in block Main 8 Temp Buffer, Network 3 Convert to 'C WTANK.SWP
5. ## How to compare word bits to a set value (Decimal or Hex)?

pfort Thank you for the help and the manual, you've made my life a whole lot easier cheers!
6. ## How to compare word bits to a set value (Decimal or Hex)?

I have 14 alarms all addressed to word 200 i.e. 200.** and i want to monitor the state of bits in word 200 such that if one of them is on the coil 204.00 should turn on (Currently i am using the OR operator to turn on bit 204.00 but the task is to use a single instruction to monitor the sate of the 16 bits of a word by comparing it to an integer say #0). I was thinking of using compare to achieve this but i do not know how to compare a word say 200 to a an integer value #0 such that if DW200>#0 then 204.00=on. How can i achieve this and what instruction can i use, am new to omron plc's and am using syswin 3.4 and plc CPM2A. Any help or sample program to achieve the above is deeply appreciated.