LK3U PLC Special relay M function description
| Special relay M function description | Remarks | ||
| M8000：Running monitoring contacts | M8001：Running monitoring anti-contact | ||
| M8002：Initializing the pulse contact | M8003：Initializing pulse anti-contact | ||
| M8004：Error indication contact | |||
| M8008：Power failure detection (when poweroff is 1, after power off is 0) | |||
| M8011：10 ms clock pulse | M8012：100 millisecond clock pulse | ||
| M8013：1 second clock pulse | M8014：1 minute clock pulse | ||
| M8015：Setting the clock | M8016：Clock display stopped | ||
| M8017：Clock plus or minus 30 seconds correction | M8019：Clock error flag | ||
| M8020：Zero mark | M8021：Borrowing sign | ||
| M8022：Carry flag | |||
| M8029：Instruction execution end flag | |||
| M8031：Non-latched data clear | M8032：Latched data clear | ||
| M8034：All outputs are disabled | M8039：Constant scan mode | ||
| M8040：STL prohibits transfer | M8046：STL action | ||
| M8047：STL monitoring is effective | M8048：S900-S999 Yes: S900-S999 has ON status | ||
| M8049：Signal alarm is valid | |||
| M8050：I0 port interrupt is forbidden | M8051：I1 port interrupt is forbidden | ||
| M8052：I2 port interrupt is forbidden | M8053：I3 port interrupt is forbidden | ||
| M8054： I4 port interrupt is forbidden | M8055：I5 port interrupt is forbidden | ||
| M8059：I010, I020, I030, I040, I050, I060 Count interrupt disabled | |||
| M8120:Start the first weighing function | M8121:The first road weighs incorrectly and cannot be reset automatically. | *1 | |
| M8122:Start the second weighing function | M8123:The second way weighs incorrectly and cannot be reset automatically. | ||
| M8124:Start the third weighing function | M8125:The third way weighing error, can not be automatically reset | ||
| M8126:Start the fourth weighing function | M8127:The fourth way weighs incorrectly and cannot be reset automatically | ||
| M8129：Serial port 1 communication timeout flag | |||
| M8139: HSCS, HSCR, HSZ, HSCT high-speed counter comparison instruction execution | |||
| M8149:CAN communication timeout flag | M8150：CAN allowed work mark | *2 | |
| M8152:User interrupt input command Y4 | M8153：User interrupt input command Y5 | *3 | |
| M8154:User interrupt input command Y6 | M8155：User interrupt input command Y7 | ||
| M8161：16-bit/8-bit switching flag | M8168：SMOV instruction HEX processing function | ||
| M8170：X0 pulse capture | M8171：X1 pulse capture | ||
| M8172：X2 pulse capture | M8173：X3 pulse capture | ||
| M8174： X4 pulse capture | M8175：X5 pulse capture | ||
| M8196：C251 C252 C254 2 multiplier flag | M8197：C253 C255 2 multiplier flag | ||
| M8198： C251 C252 C254 4 multiplier flag | M8199： C253 C255 4 multiplier flag | ||
| M8200-M8234：C200-C234 Counting direction setting | M8235-M8345：Counting direction setting of C235-C245 | ||
| M8246-M8255：C246-C255 Counting direction sign | |||
| M8329：Instruction execution ended abnormally | |||
| M8338：PLSV command acceleration and deceleration | |||
| M8340-M8349：High-speed output Y0 related function | M8350-M8359：High speed output Y1 related function | ||
| M8360-M8369：High speed output Y2 function | M8370-M8379：High speed output Y3 function | ||
| M8440-M8449：High speed output Y4 function | M8450-M8459：High speed output Y5 function | *3 | |
| M8470-M8479：High speed output Y6 function | M8480-M8489：High speed output Y7 function | ||
| M8401：RS command is being sent (M8121) | M8402：RS command transmission (M8122) | ||
| M8403：RS command reception flag (M8123) | |||
| M8409：Communication timeout flag (M8129) | |||
| M8401：Channel 1-MODBUS communication | M8421：Channel 2-MODBUS communication | *4 | |
| M8402：Channel 1- MODBUS communication error | M8422：Channel 2- MODBUS communication error | ||
| M8403：Channel 1- MODBUS communication error latch | M8423：Channel 2- MODBUS communication error latch | ||
| M8408： Channel 1 - Retry | M8428：Channel 2 - Retry | ||
| M8409：Channel 1 has timed out | M8429：Channel 2 has timed out | ||
| M8410：Channel 1/2 is switched using the ADPRW instruction | |||
| M8404：ENET is ready | M8406：Executing time setting | *5 | |
| M8411：Execution time setting | M8492：IP address save area write request | ||
| M8493：The IP address save area is written to the end | M8494：IP address save area write error | ||
| M8495：IP address save area clearing requirement | M8496：IP address save area clear ends | ||
| M8497：IP address save area clear error | M8498：Change IP address function running flag | ||
| M8460：User interrupt input command Y0 | M8461：User interrupt input command Y1 | ||
| M8462：User interrupt input command Y2 | M8463：User interrupt input command Y3 | ||
| M8464：DSZR, ZRN instruction Y0 clear signal specification is valid | M8465：DSZR, ZRN instruction Y1 clear signal specification is valid | ||
| M8466：DSZR, ZRN instruction Y2 clear signal specification is valid | M8467：DSZR, ZRN instruction Y3 clear signal specification is valid | ||
| *1 weighing function related | |||
| *2 CAN function related | |||
| *3 High speed 8-axis correlation | |||
| *4 MUDBUS function related | |||
*5 ENET network function related LK3U PLC-Communication port pin definition LK3U PLC Supported instructions LK3U PLC Special relay M function description LK3U PLC Special register D function description LK3U PLC High-speed counter instructions LK3U PLC High-speed counter instructions | |||