Function Files are a collection of status and control registers. These exist only in the MicroLogix 1200 and 1500 processors and contain the control file information for a number of instructions:
The MicroLogix 1200 supports one HSC file. The MicroLogix 1500 supports two HSC files. The High Speed Counter file uses 18-word elements.
Words 0, 1, 4, 15, 16, and 17 are addressable by word and/or bit through ladder logic.
Words 2 and 3 are addressable by bit only through ladder logic.
Words 5, 7, 9, 11, and 13 are addressable by double word only through ladder logic.
Word Bit Description
0 - PFN - Program File Number (Read Only)
1 - EC - Error Code (Read Only)
2 0 UIX - Executing User Interrupt (Read Only)
1 UIE - User Interrupt Enable (Read/Write)
2 UIL - Lost User Interrupt (Read/Write)
3 UIP - Pending User Interrupt (Read Only)
4 FE - Function Enabled (Read/Write via ladder logic; except when executing, then Read Only)
5 AS - Auto Start (Read Only)
6 ED - Error Detected (Read Only)
7-10 Reserved (Read Only)
11 CE - Counting Enabled (Read/Write)
12-14 Reserved (Read Only)
15 SP - Set Parameters (Read/Write via ladder logic; except when executing, then Read Only)
3 0 LPM - Low Preset Mask (Read/Write)
1 HPM - High Preset Mask (Read/Write)
2 UFM - Underflow Mask (Read/Write)
3 OFM - Overflow Mask (Read/Write)
4 LPI - Low preset reached, caused HSC interrupt. (Read/Write)
5 HPI - High preset reached, caused HSC interrupt. (Read/Write)
6 UFI - Underflow caused HSC interrupt (Read/Write)
7 OFI - Overflow caused HSC interrupt. (Read/Write)
8 LPR - Low Preset Reached (Read Only)
9 HPR - High Preset Reached (Read Only)
10 DIR - Count Direction (Read Only)
11 UF - Underflow (Read/Write)
12 OF - Overflow (Read/Write)
13 MD - Mode 1 Done (Read/Write)
14 CD - Count Down (Read Only)
15 CU - Count Up (Read Only)
4 - MOD - High Speed Counter Mode (Read Only) 0 - 1a 4 - 3a1 - 1b 5 - 3b2 - 2a 6 - 4a3 - 2b 7 - 4b
5 - ACC - Accumulator counted pulses (low word)
6 - ACC - Accumulator counted pulses (high word) The Low Word of the Accumulator should be read prior to reading the High Word of the Accumulator or incorrect values may result. A read of the Low Word of the Accumulator will latch the High Word of the Accumulator. In ladder logic, access to the high word is only allowed through a double word access of the low word.
7 - HIP - The value at which a high preset interrupt occurs. (Low Word) (Read/Write)
8 - HIP - The value at which a high preset interrupt occurs. (High Word) (Read/Write)
9 - LOP - The value at which a low preset interrupt occurs. (Low Word) (Read/Write)
10 - LOP - The value at which a low preset interrupt occurs. (High Word) (Read/Write)
11 - OVF - The value at which an overflow interrupt occurs. (Low Word) (Read/Write)
12 - OVF - The value at which an overflow interrupt occurs. (High Word) (Read/Write)
13 - UNF - The value at which an underflow interrupt occurs (Low Word) (Read/Write)
14 - UNF - The value at which an underflow interrupt occurs (High Word) (Read/Write)
15 - OMB - Output Mask - Defines which outputs are controlled by the High Speed Counter. (Read Only) In ladder logic, access to the high word is only allowed through a double word access of the low word.
16 - HPO - This value output through Output Mask when High Preset is reached. (Read/Write)
17 - HPO - This value output through Output Mask when Low Preset is reached. (Read/Write)