Rockwell Automation 1738-SSIM23 ArmorPoint I/O SSI Absolute Encoder Module, Series A - Manual (Page 11)

Publication 1738-IN013A-EN-E - June 2004
ArmorPoint I/O Synchronous Serial Interface (SSI) Absolute Encoder Module, Series A 11
Specifications Following are specifications for the 1738 ArmorPoint SSI Absolute
Encoder module.
ArmorPoint 1738-SSIM23 Module
Number of SSI Channels
1
Encoder Type Any absolute encoder supporting standard SSI protocol including linear, rotary, and
optical distance measuring devices.
Most-Significant Bit Aligned data format. Physical interface for clock and data signals is
RS-422.
SSI Data Rate 125kHz, 250kHz, 500kHz, 1MHz, 2MHz (software selectable)
SSI Bits Per Word 2-31 (software selectable)
SSI Word Delay Time 1 16
µs-64ms (software selectable)
SSI Word Length 4 bytes (32 bits)
SSI Features Gray or binary code capable with gray to binary conversion, increasing or decreasing SSI
count indication, 2 SSI word comparator values, SSI word latching with I1 input.
SSI Position Forming Time 2 > 0.5ms
SSI Cable Type UL CM/AWM 2464/CSA Type CMG FT4 or similar cable utilizing shielded twisted pairs
for D+/- and C+/- connections. See sensor manufacturer for actual cable required for the
SSI sensor under use. I1 input can be wired separate from SSI cable
1 .
SSI Cable Length Depends on desired SSI data rate:
125kHz - 1050ft (320m)
250kHz - 525ft (160m)
500kHz - 195ft (60m)
1MHz - 65ft (20m)
2MHz - 25ft (8m)
SSI Sensor Power
(At V +/- Terminals)
10-28.8V dc common with field power voltage, 0.75A dc maximum with short circuit
protection
SSI Clock Drive Current
(Out of Clock +/- Terminals)
125mA maximum
Input I1 IEC Type 3 voltage and current characteristics, sourcing type
Minimum Nominal Maximum
ON-State Voltage 0V dc -- FPV* -10
ON-State Current 2mA 4mA 5mA
(FPV=24V dc)
OFF-State Voltage FPV-5 -- FPV
OFF-State Current 1.2mA -- --
Input Impedance -- 3.6k Ω 4.7k Ω
Input Filter Time -- 0.5ms --
* = FPV Field Power Supply Voltage
Field Power Supply Voltage (Bus Supply) Minimum Nominal Maximum
10V dc 24V dc 28.8V dc
Keyswitch Position 2