Xinje XD Series User Manual page 363

Q14: Why data errors after using DMUL instructions?
A14:
DMUL operation instruction is 32 bit*32 bit=64 bit operation, the result occupies 4 words,
such as: EMUL D0 D2 D10, two multiplier both are 32bit (D1,D0) and (D3, D2), the result is
64 bit (D13, D12, D11, D10), so D10~D13 will be occupied. If these data registers are used
latter, operation will error.
Q15: Why the output point action errors after PLC running for a while？
A15:
It's possible that output terminal is loose, please check.
Q16: Why expansion module does not work while power indicator is ON?
A16:
It is likely the connection of module strips and PLC pins or CPU is not good. Compare the
CPU and expansion in cross contrast way to find the problems.
Q17: Why the signal input but cannot see the high speed counter working？
A17:
If high-speed counting is to be carried out, in addition to connecting high-speed pulse to the
input of high-speed counting of PLC, the corresponding high-speed counting program should
be written with functional instructions. For details, please refer to the relevant content of
Chapter 5 of this manual.
Q18: C language advantages compared to ladder chart?
A18:
(1) XD/XL series PLC supports almost all C language functions. When it comes to complex
mathematical operations, the advantage of C language is more obvious.
(2) Enhance the confidentiality of the program (when using file-advanced storage mode, C
language can not upload);
(3) C language function block can be called in many places and different files, which greatly
improves the efficiency of programmers.
Q19: What's PLC output terminal A, B？
A19:
PLC output terminal A, B are RS485 terminals of PORT2 on PLC.
Q20: What's the difference of sequence function BLOCK trigger condition: rising edge
triggered and normally closed conduction?
A20:
Rising edge triggered: when the condition is triggered, block executes in order from top to
bottom; Normally closed conduction: when the condition is triggered, Block will execute in
362