User manual HANNA INSTRUMENTS HI 504

[. . . ] HI 504 Panel-mounted, Microprocessor-based pH/ORP Process Controller Instruction Manual TABLE OF CONTENTS WARRANTY . 113 3 WARRANTY All Hanna Instruments meters are guaranteed for two years (sensors, electrodes and probes for six months) against defects in workmanship and materials when used for their intended purpose and maintained according to instructions. Damage due to accident, misuse, tampering or lack of prescribed maintenance are not covered. If service is required, contact the dealer from whom you purchased the instrument. [. . . ] Some commands are used when the master is requesting information from the controller, other when the master wants to set a parameter in the process memory (RAM or EEPROM). The master software must send the command string with a maximum delay of 20ms between each character. The program on the master must not allow setting commands other than keyboard or cleaning start/stop commands if the general password has not been entered. After the general password recognition through the "PWD" command, a 1minute time-out is let before the process meter locks again, i. e. if the PC program waits for more than 1 minute between two subsequent setting commands, the second one is not fulfilled and the "PWD" command must be issued again. 60 Following is the complete list of commands available: Command NNMDR NNHOP NNSNR NNSTS Parameter not available not available not available not available Remarks Requests firmware code (always available) Requests hardware options Requests hardware identifier (always available) Requests instrument status (relays, LEDs, configuration change flag, etc. ) Requests last pH reading (instrument configured for pH) Requests last mV reading (always available) Requests temperature reading (instrument configured for pH) Requests all last calibration data (always available) Requests setup item C. NN. (NNGET command is answered with "<ProcessID><CAN>" for the hardware identifier) Sends the general password (always available) NNPHR NNMVR NNTMR NNCAR NNGET not available not available not available not available CNN NNPWD NNSET C1C2C3C4 CNNP1P2C1C2C3C4 Sets setup item C. NN with parameter P1P2C1C2C3C4(*) (not available in setup mode) not available Requests event log file (available in idle, event scrolling or last calibration data scrolling mode w/control OFF) NNEVF 61 Command NNEVN NNAER NNCLS NNCLP NNHLD NNKDS NNKCD NNKUP NNKRG NNKST NNKCL NNKDW NNKCF NNK 02 Parameter not available not available not available not available not available null null null null null null null null null Remarks Requests new events (always available) Requests active errors (always available) To start advanced cleaning (always available) To abort cleaning (always available) To enter/exit the hold mode (always available; pwd required) Same as LCD key Same as CAL DATA key Same as Same as key key Same as SETUP key Same as CAL key Same as key Same as CFM key Same as LCD+CAL+SETUP keys (*) C1C2C3C4 are ASCII chars corresponding to the setup item content; P1P2 are two additional bytes used for sign and half digit as follows: P1 P1 P2 P2 = = = = + 0 1 if>0 if<0 if most significant digit is not used if most significant digit is used When an item is shorter than 4 digits the Ci characters are filled with blanks. 62 Following are examples for setup item format: · item C. 32, maximum relay ON time: parameter value = 15, format = "+015", where indicates a blank; · item C. 21, setpoint 2 value while in ORP mode: parameter value = -1200 mV, format = "-01200"; · item G. 01, temperature compensation: parameter value = "AtC", format = "+0*AtC". For all items with a fixed set of choices, blank spaces on the left of the value displayed are replaced with "*" (as many "*" characters are needed to reach the maximum string length, which is for example 3 for item C. 57). Blanks must be put on the tail for all items in order to have always a total length of 6 characters (see the setup table). The same parameter format used for setup item setting is used also for setup item getting (i. e. when a "NNGETCNN<CR>" command is received from the PC, the reply "NN<STX>P1P2C1C2C3C4<ETX>" is sent back). To perform a "NNSETCNN. . . " command the general password has to be sent in advance through the "NNPWD. . . " command. In particular it is not possible to access any setup item that performs a test on the instrument and it is not possible to configure the hardware identifier (setup item G. 12). Note No validity check of the sent item value is done upon reception of a "NNSETCNN<CR>" command: this check is done by Hanna HI 92500 software. The "NNSET. . . " and "NNGET. . . " commands when used for password items, baud rate, hardware identifier, F and F . 00 . 10 items, P. 00 through P. 09 items, are answered with "NN<CAN>". As soon as the process controller realizes that a command has been received, it sends one of the following answers: 1) "NN", ACK (char 0x06) if the process controller recognizes the set command and performs the requested task; 2) "NN", STX (char 0x02), DATA, ETX (char 0x03) if the re63 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 hardware 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. [. . . ] · For ORP Electrodes: polish the metal tip with a lightly abrasive paper (paying attention not to scratch the surface) and wash thoroughly with water. Note With industrial applications, it is always recommended to keep at least one spare electrode handy. When anomalies are not resolved with a simple maintenance, change the electrode (and recalibrate the controller) to see if the problem is alleviated. 106 DEFINITIONS Same as proportional band, but expressed in units of the controlled magnitude (eg. EEPROM Electrically Erasable Programmable Read-only Memory (permanent memory). FAIL SAFE ALARM Signaling of the alarm by de-energizing the alarm relay instead of energizing it. [. . . ]