PLC2 Timer question

krakenfan69

Lifetime Supporting Member
Join Date
Nov 2011
Location
Alberta
Posts
227
HI again guys,

Still converting my PLC2 project and ran into an issue with a timer. I get that the PLC2 timers Start at the 030 address and that the bit 15 is the Done bit and bit 17 is the Enabled bit. I have also sorted out that the preset is stored at an address 100 more than the timer so Timer 040 preset is at 140 memory address.
My issue is this program is using an XIC 040/02 to trigger another bit. Is this a timer timing bit?The address referencing manual shows bit 0-3 as least significant bit, 4-7 as the middle digit and 10-13 as Most significant bit. My timer has a Preset of 999. What the heck is bit 2 doing?

I'm assuming its the ACCUM and setting that bit will trigger when that binary represented value is reached. Am I totally off base here? So its on when the LSB is 4, 5, 6 or 7 then off for 0, 1, 2, 3, 8, and 9? It looks as though it is being used as a pulse timer for old panel lamps for alarms. Not much description in this logic and no drawings so I'm not positive.

Thanks,

Kraken Fan #69
 
Last edited:
You are correct, 040/02 is bit 2 of the timer accumulator. The accumulator is in BCD format. The preset is 100 (octal) higher at 140. Bit 17 is the enable and 15 is the done. There is no TT bit.
 
in the PLC2 the timers and counters can be located in any part od the data table
the timer / counter address will hold the accu value (lower 3 digits) and the status upper digit Bits 14,15 ,16,17 (Octal Base) 0-7 and 10-17
the preset will be 100 words( Octal) above the address
timer 201 will use 301 for the preset value
I have seen many programs where the timers were scattered through the full table
I have had to do it myself when adding timers
 
You are correct, 040/02 is bit 2 of the timer accumulator. The accumulator is in BCD format. The preset is 100 (octal) higher at 140. Bit 17 is the enable and 15 is the done. There is no TT bit.

Strange bit to be using. Would be on when:
007 - 009
017 - 019
.
.
997 - 999
If I have my BCD right.

Also I used to use XIC of Enable AND XIO of Done for Timer Timing.
 
the number are displayed in BCD but the data is limited to octal bits 0-7and 10-17 only there are no bits 8 and 9 also no addresses ending in 8 or 9.
address 0-7, 10-17,20-27,30-17 ect.... you can use HEX numbers but they don't work with timers or counters and the table runs continuous a 100 word table will cross over to the next number set 00-77 100-107
 
the PLC2's use a 16 bit word it's just divided in 2 8 bit words 0 bits 0-7 and 10-17
if you are using bits then all 16 bits are used but when you use numbers you can use all the bits but the data will be in Hex format 0-F or 0000-FFFF for each 16 bit word so you will see data shown hex format. counters and timers only use decimal numbers the other bits are just not used. if you are editing the data table be careful you can address all the bits in any valid address you can really mess-up a program quickly just by changing 1 bit in timer
 
Thanks to all who have replied. (Doug -P, I have that manual already but never saw a reference to using just one bit) It appears to indeed be a pulse for a flasher. Albeit a strange one.

Thanks again,

Kraken Fan #69
 

Similar Topics

Hello All, I am working with an old PLC2 and we had some kind of power surge that screwed our program up. I have gone back with an old hardcopy...
Replies
5
Views
4,770
OK, so I have seen the threads pop up and I had been doing some research into getting over this hurdle for a bit after I ran into some of these...
Replies
3
Views
727
Hello, I was wondering if anyone would be able to help me out; I have a PLC2 file that I can't access (I don't have the software). Would anyone...
Replies
3
Views
758
I want to start this by saying all the following is for curiosity sake only, no real world / production ramifications come along. Inspiration...
Replies
24
Views
6,137
Hello, I am using a Digi One IAP and CompactLogix PLC to read some Modbus registers from a Kohler Generator. Things are working, except when I...
Replies
1
Views
1,227
Back
Top Bottom