Appendix C
Memory Areas
583
Word(s)
Page
Read/
write
Function
Bit(s)
SR 252
00
Not used. (system use)
01 to 07
Not used.
08
Peripheral Port Reset Bit
Turn ON to reset peripheral port. (Not valid when Programming Device is
connected.) Automatically turns OFF when reset is complete.
Read/
write
272
09
RS-232C Port Reset Bit
Automatically turns OFF when reset is complete.
10
PC Setup Reset Bit
Turn ON to initialize PC Setup (DM 6600 through DM 6655). Automatically
turns OFF again when reset is complete. Only effective if the PC is in PRO-
GRAM mode.
2
11
Forced Status Hold Bit
OFF: The forced status of bits that are forced set/reset is cleared when
switching between PROGRAM mode and MONITOR mode.
ON: The status of bits that are forced set/reset are maintained when switch-
ing between PROGRAM mode and MONITOR mode.
17
12
I/O Hold Bit
OFF: IR and LR bits are reset when starting or stopping operation.
ON: IR and LR bit status is maintained when starting or stopping operation.
17
13
Not used.
14
Error Log Reset Bit
Turn ON to clear error log. Automatically turns OFF again when operation is
complete.
Read/
write
555
15
Not used.
SR 253
00 to 07
FAL Error Code
The error code (a 2-digit number) is stored here when an error occurs. The
FAL number is stored here when FAL(06) or FALS(07) is executed. This word
is reset (to 00) by executing a FAL 00 instruction or by clearing the error from
a Programming Device.
Read-
only
385
08
Not used.
09
Cycle Time Overrun Flag
Turns ON when a cycle time overrun occurs.
Read-
only
---
10 to 11
Not used.
12
RS-232C Port Set Bit
Turn ON to set RS-232C port.
Turn OFF when reset is complete.
Read/
write
13
Always ON Flag
Read-
l
---
14
Always OFF Flag
only
---
15
First Cycle Flag
Turns ON for 1 cycle at the start of operation.
---
SR 254
00
1-minute clock pulse (30 seconds ON; 30 seconds OFF)
---
01
0.02-second clock pulse (0.01 second ON; 0.01 second OFF)
---
02
Negative (N) Flag
---
03
Not used.
04
Overflow Flag
Read-
l
---
05
Underflow Flag
only
---
06
Differential Monitor Complete Flag
Turns ON when differential monitoring is complete.
159
07
STEP(08) Execution Flag
Turns ON for 1 cycle only at the start of process based on STEP(08).
385
08 to 15
Not used.