DL305 - DL330/340 CPUs Frequently Asked Questions
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Question:
I can't edit control relays from data view with a D3-330 or D3-340. What am I doing wrong?
Answer
You're not doing anything wrong. The D3-330 and D3-340 use Direct Net protocol only. You can only write at a byte level with DirectNet. You must edit the entire R register containing the C bit you wish to change. You should examine the R register containing the C bit and edit the entire register with the BCD value that would reflect the bit pattern you're wanting. The D3-350 also uses DirectNet and you can do the same thing editing V-memory. Better yet, with the D3-350 you can switch to K-Sequence protocol and do bit level reads and writes.
FAQ ID: 98
Question:
Why can I successfully connect with DirectSOFT to a D3-330 with my DCU, but when I put my DCU on a D3-330P, I cannot connect?
Answer
To connect to a D3-330P, dipswitch 6, block 1 (PGM mode at power up) has to be ON.
FAQ ID: 102
Question:
Do I have to use Stage programming in D3-330P?
Answer
Yes, you have to have at least one stage; i.e. ISG 0.
FAQ ID: 103
Question:
Which special relay do I use for "always on" with a D3-330 or D3-340?
Answer
Use STR NOT C374, being C374 one internal relay that closes only on the fist CPU scan. This will be on for all scans except first scan. If you also need first scan, use STR NOT C374 OR STR C374.
FAQ ID: 104
Question:
Can I do Peer-to-Peer networking between two D3-340s?
Answer
No.
The D3-340 only supports Master/Slave networking. There is a misprint in the 305 User Manual.
That is, one the master can initiate communications. Peer-to-peer communications allows that every device can initiate communications.
FAQ ID: 105
Question:
Some of the counters and timers are not working in my D3-330 or D3-340. What's wrong?
Answer
This may be the result of using timers and counters with the same number. For example, Timer 600 and Counter 600. The timers and counters share the same memory area in a D3-330/D3-340 CPU. You cannot use the same number for both a timer and a counter.
FAQ ID: 106
Question:
The battery LED is illuminated on by DL305. How do I replace the battery without losing the program?
Answer
You should always make a backup copy of the program using either the Handheld programmer with a cassete tape or using DirectSOFT with a DCU (Data Communications Unit) if at all possible. Then, power down the DL305, remove the old battery and install a new battery (D3-D4-BAT). The memory is capacitor backed and will last several minutes allowing time to replace the old battery.
FAQ ID: 109
Question:
I have a GE Series 1 RS-422 DCU. What do I need to communicate to my RS-232-C port on my computer?
Answer
A FA-UNICON and a D2-DSCBL will be needed. The UNICON will plug directly on the DCU converting RS-422 to RS-232. A converter supplied with the UNICON will convert the RS-232 side of the UNICON to a RJ-12 modular connector. The D2-DSCBL will plug into the converter allowing a connection to a DB9 connector on the PC.
FAQ ID: 110
Question:
Why won't the DDE server read from my D3-330?
Answer
The password in the PLC is not allowing access.
FAQ ID: 120
Question:
Can I do "online edits" to D3-330 or D3-340 CPUs?
Answer
No.
FAQ ID: 122
Question:
Where can I locate a Modbus cross-reference table for a D3-340 CPU?
Answer
Printed table Xref Document
There is a Excel spreadsheet for calculating the Modbus-Koyo conversion address. Modbus Spreadsheet Use the "340 Modbus" sheet
FAQ ID: 127
Question:
Can the D3-DCM be a Modbus master?
Answer
No it can't.
FAQ ID: 700
Question:
Q: Can I use the D2-DSCBL with a D3-340?
Answer
A: No; use instead the cable D3-DSCBL-1
FAQ ID: 788
Question:
Can I remove a RAM chip from a 330 CPU and move to another CPU? So I can transfer the project if communications is unavailable?
Answer
There is only 1 slot on a 330 CPU. There could be various chip types, but the standard is RAM.
The RAM chip depends on the battery and capacitor on the circuit board to retain the project. If the RAM is removed, the project would be lost.
ONLY the EEPROM or UVPROM chips would be able to be removed and transferred without loss of program.
FAQ ID: 1566
Question:
Can a message be displayed on the D3-HP by the PLC?
Answer
Only thru the FAULT instruction, the HP isn't designed to be a display.
FAQ ID: 1567
Question:
Why is DirectSoft asking for a password for brand new CPU/EEPROM?
Answer
The new hardware will not have a password. However, noise can cause this issue, and if using a D3-232-DCU, then incorrect port settings between the DCU and DirectSoft can definitely cause this issue.
FAQ ID: 1598