23: INTELLIGENT MODULE ACCESS INSTRUCTIONS23-4 « FC4A MICRO SMART USER ’S MANUAL »STPA READ (Stop Access Read)Note: STPA READ and STPA WRITE instructions can be used 64 times in a user program. When more than 64 STPA READand STPA WRITE instructions are used in a user program, the excess instructions are not executed and error code 7 isstored in the data register designated as STATUS.Applicable CPU ModulesValid Operands (Stop Access Read)For the valid operand number range, see pages 6-1 and 6-2.DATA: Specify the first operand number to store the data read from the intelligent module.▲ Internal relays M0 through M1277 and AS-Interface internal relays M1300 through M1997 can be desig-nated as DATA. Special internal relays cannot be designated as DATA.When T (timer) or C (counter) is used as DATA for Stop Access Read, the data read from the intelligentmodule is stored as a preset value which can be 0 through 65535.All data registers, including special data registers, AS-Interface data registers, and expansion data registers,can be designated as DATA.STATUS: Specify a data register to store the operating status code. Only data registers D0 through D1299 can be des-ignated as STATUS. Special data registers, AS-Interface data registers, and expansion data registers cannotbe designated whether the AS-Interface master module is used or not. For status code description, seepage 23-6.SLOT: Enter the slot number where the intelligent module is mounted. A maximum of seven intelligent modulescan be used.ADDRESS: Specify the first address in the intelligent module to read data from.BYTE: Specify the quantity of data to read in bytes.The STPA READ instruction cannot be used in an interrupt program. If used, a user program execution error will result,turning on special internal relay M8004 and the ERR LED on the CPU module.If a STPA READ instruction is programmed between MCS and MCR instructions, the STPA READ instruction is exe-cuted when the CPU module is stopped regardless whether the input condition for the MCS instruction is on or off. ForMCS and MCR instructions, see page 7-23.Valid Data TypesFC4A-C10R2/C FC4A-C16R2/C FC4A-C24R2/C FC4A-D20K3/S3 FC4A-D20RK1/RS1 & FC4A-D40K3/S3— — X X XOperand Function I Q M R T C D Constant RepeatDATA First operand number to store read data — X ▲ X X X X — —STATUS Operating status code — — — — — — X — —SLOT Intelligent module slot number — — — — — — — 1-7 —ADDRESS First address in intelligent module to read data from — — — — — — — 0-127 —BYTE Bytes of data to read — — — — — — — 1-127 —W (word) I (integer)X XWhen the CPU module stops, data is read fromthe area starting at ADDRESS in the intelligentmodule designated by SLOT and stored to theoperand designated by DATA.BYTE designates the quantity of data to read.STATUS stores the operating status code.DATA*****SLOT*STATUS*****BYTE***ADDRESS***STPA(*)READStart input is not needed for this instruction.When a bit operand such as I (input), Q (output), M (internal relay), or R (shift register) isdesignated as DATA, 16 points are used.When a word operand such as T (timer), C (counter), or D (data register) is designated asDATA, 1 point is used.
