6 7
1. Liquid Crystal Display
2. ON/OFF key, to turn the HI 504920 on and off.
3. ALT key, to activate alternate key functions
4. DISPLAY / CAL DATA key, to enter/exit the event scrolling mode, to view pH
buffer or °C while calibrating pH, and to view last calibra-
tion data (with ALT)
5. TXCAL key, for quick single point pH calibration
6. æ SETUP key, to move up or enter/exit the Setup mode (with ALT)
7. CAL key, to move right or enter/exit the calibration mode (with ALT)
8. CALT key, to move down (no alternate function for HI 504910)
9. CFM key, to confirm values.
The device can be restarted at any time by pressing CFM,
ALT and æ SETUP together (CFM first)
Keyboard and LCD for HI 504910 are normally provided
by HI 504920. To do this, HI 504920 has to be put
into terminal mode, by selecting code 90 in Setup
mode.
If the HI 504920 meter is not handy, the keyboard and
LCD inside the transmitter case can be used for configur-
ing, calibrating and monitoring HI 504910.
FUNCTIONAL DESCRIPTION
1. Infrared optical interface for HI504920
2. Cable glands for 24 VDC power supply, for HI504
or computer workstation connection, for pH (or
ORP) electrode & temperature probe inputs
3. Cable gland for Matching Pin connection
4. Power supply input (24V AC/DC)
5. RS485 connections to HI504, PC, modem, GSM
module
6. Connections for Pt100/Pt1000 temperature sensor
7. Connection for Potential Matching Pin
8. Connection for electrode reference
9. Connection for pH or ORP electrode input
10. Protecting shield: remove to access connectors;
reattach after wiring.
11. Green status LED
12. Red status LED
