User Guide

64
ceived command is a request of data;
3) “NN”, NAK (char 0x15) if the process controller does not
recognize the command or if the command syntax is wrong;
4) “NN”, CAN (char 0x18) if the process controller can not
answer to the request (e.g. the current process model does
not support the request, the given general password is
wrong, etc.)
The “NN” in the front of the answer is the Process ID
(“00” to “99”).
The time-out for the above answers is:
1) answer to “STS”, “PHR”, “MVR”, “TMR”, “AER” commands:
30 ms @ 19200 or 9600 bit/s, 40 ms @ 4800 bit/s, 60 ms
@ 1200 bit/s (for the complete answer, from STX to ETX).
2) answer to other commands: 2s (for the first character of the
answer).
The minimum delay between the last received and the first
sent character is 15 ms to allow the master to set itself into
receiving mode.
Here are descriptions of the answers format (for setup item
request see above):
The NNSNR request produces the following answer:
“NN<STX><7-character long ASCII string representing hard-
ware identifier><ETX>” (e.g. “29<STX>1234567<ETX>” if
the Process ID alias RS485 address is 29 and the hardware
identifier is 1234567).
The NNGET command is answered with “NN<CAN>” when
used for the hardware identifier.
The NNMDR request produces the following answer:
“NN<STX>FP504XYZVV--ABCD<ETX>”
where VV is the firmware version, e.g.”10” for 1.0;
XYZ are the three model digits, e.g. XYZ=214 for dual setpoint,
ON/OFF and PID control, dual analog output;
AB is the first HI 92500 software version compatible with the
firmware, even if it may not be able to exploit all the features of
the firmware, e.g. “34” for 3.4;
CD is the first HI 92500 software version fully compatible with
this firmware, e.g. “45” for 4.5.