| Attribute | | 1746-BAS | 1746-BAS-T |
| Memory Size | | 24 Kbytes battery-backed RAM | 24 Kbytes battery-backed RAM |
| Optional Memory Modules | | 1747-M1
1747-M2 | 1771-DBMEM1
1771-DBMEM2 |
| Power supply
loading | 5V DC | 0.150 | |
| 24V DC | 0.040 | |
| Port
configuration | PRT1 | RS-232/423, RS-422, RS-485 | |
| PRT2 | RS-232/423, RS-422, RS-485 | |
| DH-485 | DH-485 | |
| Port isolation | Backplane to PRT1 | 710V DC for 1 minute | |
| Backplane to PRT2 | 710V DC for 1 minute | |
| PRT1 to PRT2 | 710V DC for 1 minute | |
| Maximum
communication
distance | RS-232 (300…19200 bps) | 15 m (50 ft) | |
| RS-423 (300 bps) | 1230 m (4000 ft) | |
| RS-423 (600 bps) | 920 m (3000 ft) | |
| RS-423 (1200 bps) | 770 m (2500 ft) | |
| RS-423 (4800 bps) | 245 m (800 ft) | |
| RS-423 (9600 bps) | 120 m (400 ft) | |
| RS-423 (19200 bps) | 60 m (200 ft) | |
| RS-422 (300…19200 bps) | 1230 m (4000 ft) | |
| RS-485 (300…19200 bps) | 1230 m (4000 ft) | |
| Data Transfer | SLC 5/01 | 8 input words (SLC input image table)
8 output words (SLC output image table) | |
| SLC 5/02 and higher | 8 input words (SLC input image table)
8 output words (SLC output image table)
64 input and 64 output words (SLC M0/M1 file) | |
| Data Rates | | 300…19,200 baud | |
| Modem support | | DF1 half-duplex slave or full duplex | |
| Clock/calendar accuracy | | ±1 minute/month @ 25 °C (77 °F)
0, -6 minutes/month @ 60 °C (140 °F) | |